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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. 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.

  6. 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 ...

  7. 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.

  8. Edentulism and dental prostheses in the elderly: impact on quality of life measured with EuroQol--visual analog scale (EQ-VAS).

    Science.gov (United States)

    Cano-Gutiérrez, Carlos; Borda, Miguel G; Arciniegas, Antonio J; Borda, Claudia X

    2015-01-01

    The objective of this study was to measure the impact of edentulism and dental prostheses on quality of life (QOL) in older adults in Bogota, Colombia. Edentulism is a frequent condition in older adults and has great impact on their QOL. No epidemiological data are currently available on edentulism among older adults in Colombia. Data were obtained from the SABE-Bogota study, a cross-sectional study conducted in 2012, and used to analyze the EQ-VAS (Visual Analog Scale) from the EuroQol instrument to measure the perception of quality of life (QOL) in relation to edentulism. The study included 2,000 individuals over 60 years old. The Spearman-Rho correlation was used to analyze the correlation between EQ-VAS and edentulism. Chi-Square, ANOVA and t-test were used to study the differences in EQ-VAS scores between edentulous and healthy subjects. Statistical significance was set at peducation were related to edentulism. Individuals with fewer teeth and dental prostheses had lower EQ-VAS scores (pmeasuring the perception of QOL in dental health scenarios. Edentulism significantly affects QOL in older adults and the use of dental prosthesis does not improve the perception of QOL.

  9. 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.

  10. An approach for brain-controlled prostheses based on Scene Graph Steady-State Visual Evoked Potentials.

    Science.gov (United States)

    Li, Rui; Zhang, Xiaodong; Li, Hanzhe; Zhang, Liming; Lu, Zhufeng; Chen, Jiangcheng

    2018-08-01

    Brain control technology can restore communication between the brain and a prosthesis, and choosing a Brain-Computer Interface (BCI) paradigm to evoke electroencephalogram (EEG) signals is an essential step for developing this technology. In this paper, the Scene Graph paradigm used for controlling prostheses was proposed; this paradigm is based on Steady-State Visual Evoked Potentials (SSVEPs) regarding the Scene Graph of a subject's intention. A mathematic model was built to predict SSVEPs evoked by the proposed paradigm and a sinusoidal stimulation method was used to present the Scene Graph stimulus to elicit SSVEPs from subjects. Then, a 2-degree of freedom (2-DOF) brain-controlled prosthesis system was constructed to validate the performance of the Scene Graph-SSVEP (SG-SSVEP)-based BCI. The classification of SG-SSVEPs was detected via the Canonical Correlation Analysis (CCA) approach. To assess the efficiency of proposed BCI system, the performances of traditional SSVEP-BCI system were compared. Experimental results from six subjects suggested that the proposed system effectively enhanced the SSVEP responses, decreased the degradation of SSVEP strength and reduced the visual fatigue in comparison with the traditional SSVEP-BCI system. The average signal to noise ratio (SNR) of SG-SSVEP was 6.31 ± 2.64 dB, versus 3.38 ± 0.78 dB of traditional-SSVEP. In addition, the proposed system achieved good performances in prosthesis control. The average accuracy was 94.58% ± 7.05%, and the corresponding high information transfer rate (IRT) was 19.55 ± 3.07 bit/min. The experimental results revealed that the SG-SSVEP based BCI system achieves the good performance and improved the stability relative to the conventional approach. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Developing Tests of Visual Dependency

    Science.gov (United States)

    Kindrat, Alexandra N.

    2011-01-01

    Astronauts develop neural adaptive responses to microgravity during space flight. Consequently these adaptive responses cause maladaptive disturbances in balance and gait function when astronauts return to Earth and are re-exposed to gravity. Current research in the Neuroscience Laboratories at NASA-JSC is focused on understanding how exposure to space flight produces post-flight disturbances in balance and gait control and developing training programs designed to facilitate the rapid recovery of functional mobility after space flight. In concert with these disturbances, astronauts also often report an increase in their visual dependency during space flight. To better understand this phenomenon, studies were conducted with specially designed training programs focusing on visual dependency with the aim to understand and enhance subjects ability to rapidly adapt to novel sensory situations. The Rod and Frame test (RFT) was used first to assess an individual s visual dependency, using a variety of testing techniques. Once assessed, subjects were asked to perform two novel tasks under transformation (both the Pegboard and Cube Construction tasks). Results indicate that head position cues and initial visual test conditions had no effect on an individual s visual dependency scores. Subjects were also able to adapt to the manual tasks after several trials. Individual visual dependency correlated with ability to adapt manual to a novel visual distortion only for the cube task. Subjects with higher visual dependency showed decreased ability to adapt to this task. Ultimately, it was revealed that the RFT may serve as an effective prediction tool to produce individualized adaptability training prescriptions that target the specific sensory profile of each crewmember.

  12. A Visual Test for Visual "Literacy."

    Science.gov (United States)

    Messaris, Paul

    Four different principles of visual manipulation constitute a minimal list of what a visually "literate" viewer should know about, but certain problems exist which are inherent in measuring viewers' awareness of each of them. The four principles are: (1) paraproxemics, or camera work which derives its effectiveness from an analogy to the…

  13. Development of a Computerized Visual Search Test

    Science.gov (United States)

    Reid, Denise; Babani, Harsha; Jon, Eugenia

    2009-01-01

    Visual attention and visual search are the features of visual perception, essential for attending and scanning one's environment while engaging in daily occupations. This study describes the development of a novel web-based test of visual search. The development information including the format of the test will be described. The test was designed…

  14. 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...

  15. A computerized pre-clinical test for cemented hip prostheses based on finite element techniques

    NARCIS (Netherlands)

    Stolk, Jan

    2003-01-01

    Despite the success of cemented total hip replacement (THR), high failure rates are occasionally reported for cemented hip implants that are introduced on the orthopaedic market. Rigorous pre-clinical testing of hip implants could prevent these disasters, by detecting unsafe implant designs at a

  16. Textile for heart valve prostheses: fabric long-term durability testing.

    Science.gov (United States)

    Heim, Frederic; Durand, Bernard; Chakfe, Nabil

    2010-01-01

    The rapid developments and success in percutaneous vascular surgery over the last two decades with the now common stent grafts implantation, make the noninvasive surgery technique today attractive even for heart valve replacement. Less traumatic for the patient and also less time consuming, percutaneous heart valve replacement is however at its beginning and restricted to end of life patients. The noninvasive procedure expects from the heart valve prosthesis material to be resistant and adapted to folding requirements of the implantation process (catheter). Polyester fabric could be a suited material for heart valve implanted percutaneously. Highly flexible and resistant, polyester fabric proved to be well adapted to the dynamic behavior of a valve and polyester (Dacron) is also widely used for vascular grafts implantation and shows good biocompatibility and durability. However, today there's no data available on long-term durability of fabric used as heart valve material. The purpose of this work is to study the long term behavior of a microdenier polyester fabric construction under combined in vitro flexure and tension fatigue stress. In the novel in vitro testing technique presented, a fabric specimen was subjected to combined flexural and tensile fatigue generated by fluid flow under physiological pressure conditions. The results obtained show how flexural properties change with fatigue time, which reflects directly on the suitability of a fabric in such devices. It was also observed that these fabric structural changes directly influence the in vitro behavior of the textile heart valve prosthesis. (c) 2009 Wiley Periodicals, Inc.

  17. 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.

  18. 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.

  19. Sensitive visual test for concave diffraction gratings.

    Science.gov (United States)

    Bruner, E. C., Jr.

    1972-01-01

    A simple visual test for the evaluation of concave diffraction gratings is described. It is twice as sensitive as the Foucault knife edge test, from which it is derived, and has the advantage that the images are straight and free of astigmatism. It is particularly useful for grating with high ruling frequency where the above image faults limit the utility of the Foucault test. The test can be interpreted quantitatively and can detect zonal grating space errors of as little as 0.1 A.

  20. REDUCED THROMBOGENICITY OF VASCULAR PROSTHESES BY COATING WITH ADP-ASE

    NARCIS (Netherlands)

    VANDERLEI, B; ROBINSON, PH; BAKKER, WW; Bartels, H.

    1992-01-01

    In this pilot study ADP-ase coated polyurethane (PL) vascular prostheses and noncoated (control) PU vascular prostheses (all vascular prostheses: ID 1.5 mm, length 1,5 cm) were implanted into the carotid artery of the rabbit to test wheter ADP-ase might function as an adequate anti-thrombogenic

  1. Guideline for penetrant testing on welds by indirect visual test

    International Nuclear Information System (INIS)

    Tanaka, Isao; Taguchi, Tetsuo; Asano, Toshio; Sakai, Kaoru; Sato, Takemitsu; Takagi, Mikio

    1999-01-01

    A study of guidelines for penetrant testing on welds by indirect visual test using image processing is presented. Due to penetrant testing regulations by direct visual test, a porosity (a round defect) whose diameter is under 1.0 mm is allowed, but no crack (a line-shaped defect) is allowed, and the allowable defect size is not clear. It was found in the investigation that the smallest line-shaped indication which the inspectors could recognize was 0.15 mm in width and 0.5 mm in length. This means that the limit of line pair which all inspectors could discriminate was 3.3. A TV camera was used to take pictures of the NSIT (National Institute of Standards and Technology) (NBS: National Bureau of Standard) resolution chart and the smallest indication above, and the limit of line pair which all inspectors could discriminate was 3.6. Therefore, it is recommended as a guideline for penetrant testing through a TV camera by indirect visual test that the resolution of 3.6 line pair per mm is required and a reference test piece be defined to assure the resolution. (author)

  2. Guideline for penetrant testing on welds by indirect visual test

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Isao; Taguchi, Tetsuo [Hitachi Ltd., Ibaraki (Japan). Hitachi Works; Asano, Toshio; Sakai, Kaoru; Sato, Takemitsu; Takagi, Mikio

    1999-07-01

    A study of guidelines for penetrant testing on welds by indirect visual test using image processing is presented. Due to penetrant testing regulations by direct visual test, a porosity (a round defect) whose diameter is under 1.0 mm is allowed, but no crack (a line-shaped defect) is allowed, and the allowable defect size is not clear. It was found in the investigation that the smallest line-shaped indication which the inspectors could recognize was 0.15 mm in width and 0.5 mm in length. This means that the limit of line pair which all inspectors could discriminate was 3.3. A TV camera was used to take pictures of the NSIT (National Institute of Standards and Technology) (NBS: National Bureau of Standard) resolution chart and the smallest indication above, and the limit of line pair which all inspectors could discriminate was 3.6. Therefore, it is recommended as a guideline for penetrant testing through a TV camera by indirect visual test that the resolution of 3.6 line pair per mm is required and a reference test piece be defined to assure the resolution. (author)

  3. 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

  4. 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)

  5. The four-meter confrontation visual field test.

    OpenAIRE

    Kodsi, S R; Younge, B R

    1992-01-01

    The 4-m confrontation visual field test has been successfully used at the Mayo Clinic for many years in addition to the standard 0.5-m confrontation visual field test. The 4-m confrontation visual field test is a test of macular function and can identify small central or paracentral scotomas that the examiner may not find when the patient is tested only at 0.5 m. Also, macular sparing in homonymous hemianopias and quadrantanopias may be identified with the 4-m confrontation visual field test....

  6. 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

  7. Longitudinal research on the oral environment of elderly wearing fixed or removable prostheses.

    Science.gov (United States)

    Tanaka, Junko; Tanaka, Masahiro; Kawazoe, Takayoshi

    2009-04-01

    The purpose of this study was to investigate oral environmental risk factors involved in caries incidence in the elderly. We investigated the relationship between the oral environment factors of the elderly with both fixed prostheses and removable prostheses at baseline and at follow-up and examined time-course changes of each oral environmental factor by prosthesis type. The subject group consisted 11 elderly patients with fixed prostheses and 11 who wore removable prostheses. We examined oral environmental factors by saliva tests. Five oral environmental factors were examined: the stimulated salivary flow rate, buffering capacity, and the counts of mutans streptococci (SM), lactobacilli (LB), and Candida (CA). We compared these factors for subjects with fixed prostheses and those wearing removable prostheses at baseline and at follow-up. Furthermore, 3-year changes in the factors of each oral environment were compared and evaluated. Significant differences were observed between the two groups in the salivary microbial counts of SM and LB at baseline and at follow-up. The LB counts increased in the Denture group during the 3-year period and significant differences were noted. We found that fixed prostheses are less cariogenic, and removable prostheses cause an increase in the cariogenic bacterial count. Regarding time-course changes by the type of prosthesis, the LB count tended to increase in the subjects with removable prostheses. The risk of caries due to a fixed prosthesis may be lower than that of removable prostheses.

  8. Characterizing the Mechanical Properties of Running-Specific Prostheses

    Science.gov (United States)

    Beck, Owen N.; Taboga, Paolo; Grabowski, Alena M.

    2016-01-01

    The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (prunning 3 m/s and 6 m/s (10°-25°) compared to neutral (0°) (pRunning-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness. PMID:27973573

  9. [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

  10. 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.

  11. 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

  12. Articulation prostheses made of polymers which are improved by ionizing radiations

    International Nuclear Information System (INIS)

    Gaussens, G.; Nicaise, M.; Tran, K.O.

    1981-10-01

    Articulation prostheses for the human body are generally made of the couple very high molecular weight polyethylene-special steels. Polyethylene properties are modified by ionizing radiations: creep resistance is improved and friction coefficient is decreased. Modifications are controlled by the choice of radiation dose and dose rate. Wear tests have been made on hip prostheses [fr

  13. Microbial biofilms on silicone facial prostheses

    NARCIS (Netherlands)

    Ariani, Nina

    2015-01-01

    Facial disfigurements can result from oncologic surgery, trauma and congenital deformities. These disfigurements can be rehabilitated with facial prostheses. Facial prostheses are usually made of silicones. A problem of facial prostheses is that microorganisms can colonize their surface. It is hard

  14. Testing of Visual Field with Virtual Reality Goggles in Manual and Visual Grasp Modes

    Directory of Open Access Journals (Sweden)

    Dariusz Wroblewski

    2014-01-01

    Full Text Available Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1 manual, with patient response registered with a mouse click, and (2 visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1 minimal systematic differences between measurements taken in visual grasp and manual modes, (2 the average standard deviation of the difference distributions of about 5 dB, and (3 a systematic shift (of 4–6 dB to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients’ acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode.

  15. Testing of visual field with virtual reality goggles in manual and visual grasp modes.

    Science.gov (United States)

    Wroblewski, Dariusz; Francis, Brian A; Sadun, Alfredo; Vakili, Ghazal; Chopra, Vikas

    2014-01-01

    Automated perimetry is used for the assessment of visual function in a variety of ophthalmic and neurologic diseases. We report development and clinical testing of a compact, head-mounted, and eye-tracking perimeter (VirtualEye) that provides a more comfortable test environment than the standard instrumentation. VirtualEye performs the equivalent of a full threshold 24-2 visual field in two modes: (1) manual, with patient response registered with a mouse click, and (2) visual grasp, where the eye tracker senses change in gaze direction as evidence of target acquisition. 59 patients successfully completed the test in manual mode and 40 in visual grasp mode, with 59 undergoing the standard Humphrey field analyzer (HFA) testing. Large visual field defects were reliably detected by VirtualEye. Point-by-point comparison between the results obtained with the different modalities indicates: (1) minimal systematic differences between measurements taken in visual grasp and manual modes, (2) the average standard deviation of the difference distributions of about 5 dB, and (3) a systematic shift (of 4-6 dB) to lower sensitivities for VirtualEye device, observed mostly in high dB range. The usability survey suggested patients' acceptance of the head-mounted device. The study appears to validate the concepts of a head-mounted perimeter and the visual grasp mode.

  16. 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

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

    OpenAIRE

    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

    Background 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....

  18. 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.

  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

    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...... 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...

  20. 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...

  1. Laser vibrometer measurements and middle ear prostheses

    Science.gov (United States)

    Flock, Stephen T.; Dornhoffer, John; Ferguson, Scott

    1997-05-01

    One of us has developed an improved partial ossicular replacement prosthesis that is easier to implant and, based on pilot clinical measurements, results in better high-frequency hearing as compared to patients receiving one of the alternative prostheses. It is hypothesized that the primary reason for this is because of the relatively light weight (about 25 mg) and low compliance of the prosthesis, which could conceivably result in better high frequency vibrational characteristics. The purpose of our initial work was to develop an instrument suitable for objectively testing the vibrational characteristics of prostheses. We have developed a laser based device suitable for measuring the vibrational characteristics of the oval window or other structures of the middle ear. We have tested this device using a piezoelectric transducer excited at audio frequencies, as well as on the oval window in human temporal bones harvested from cadavers. The results illustrate that it is possible to non-invasively monitor the vibrational characteristics of anatomic structures with a very inexpensive photonic device.

  2. 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

  3. 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.

  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. 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.

  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. [New visual field testing possibilities (a preliminary report)].

    Science.gov (United States)

    Erichev, V P; Ermolaev, A P; Antonov, A A; Grigoryan, G L; Kosova, D V

    2018-01-01

    There are currently no portable mobile perimeters that allow visual field testing outside ophthalmologist's examination rooms. To develop a mobile perimetry technique based on use of a virtual reality headset (VR). The study involved 26 patients (30 eyes) with II-III stage primary open-angle glaucoma (POAG) with compensated IOP. Perimetry was performed for each patient twice - on Humphrey analyzer (test 30-2, 76 points) and employing similar strategy on a perimeter integrated into VR headset (Total Vision, Russia). Visual field testing was performed with an interval from 1 hour to 3 days. The results were comparatively analyzed. Patients tolerated the examination well. Comparative analysis of preliminary perimetry results obtained with both methods showed high degree of identity, so the results were concluded to be comparable. By visually isolating the wearer, VR headset achieves elimination of distractions and stable light conditions for visual field testing. The headset-perimeter is compact, mobile, easily transportable, can be used in the work of visiting medical teams and for examination at home.

  8. Results of the Intelligence Test for Visually Impaired Children (ITVIC).

    Science.gov (United States)

    Dekker, R.; And Others

    1991-01-01

    Statistical analyses of scores on subtests of the Intelligence Test for Visually Impaired Children were done for two groups of children, either with or without usable vision. Results suggest that the battery has differential factorial and predictive validity. (Author/DB)

  9. Stand for visual ultrasonic testing of spent fuel

    International Nuclear Information System (INIS)

    Czajkowski, W.; Borek-Kruszewska, E.

    2001-01-01

    A stand for visual and ultrasonic testing of spent fuel, constructed under Strategic Governmental Programme for management of spent fuel and radioactive waste, is presented in the paper. The stand, named 'STEND-1', built up at the Institute of Atomic Energy in Swjerk, is appointed for underwater visual testing of spent fuel elements type MR6 and WWR by means of TV-CCD camera and image processing system and for ultrasonic scanning of external surface of these elements by means of video scan immersion transducer and straight UHT connector. 'STEND-1' is built using flexible in use, high-tensile, anodized aluminum profiles. All the profiles feature longitudinal grooves to accommodate connecting elements and for the attachment of accessories at any position. They are also characterised by straight-through core bores for use with standard fastening elements and to accommodate accessory components. Stand, equipped with automatic control and processing system based on personal computer, may be manually or automatically controlled. Control system of movements of the camera in the vertical axis and rotational movement of spent fuel element permits to fix chosen location of fuel element with accuracy better than 0.1 mm. High resolution of ultrasonic method allows to record damages of outer surface of order 0.1 mm. The results of visual testing of spent fuel are recorded on video tape and then may be stored on the hard disc of the personal computer and presented in shape of photo or picture. Only selected damage surfaces of spent fuel elements are tested by means of ultrasonic scanning. All possibilities of the stand and results of visual testing of spent fuel type WWR are presented in the paper. (author)

  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. Magnetic resonance imaging of breast prostheses

    African Journals Online (AJOL)

    G5

    and the commonest cause of replacement of the prosthesis. Older prostheses contained silicone gel. Rupture of these prostheses, although asymptomatic in most patients, has been associated with collagen vascular disorders and chronic fatigue syndrome. However more current data disputes any of these associations.

  12. 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.

  13. 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.

  14. Implant-level prostheses in the edentulous maxilla: a comparison with conventional abutment-level prostheses after 5 years of use.

    Science.gov (United States)

    Hjalmarsson, Lars; Smedberg, Jan-Ivan; Pettersson, Mattias; Jemt, Torsten

    2011-01-01

    Long-term comparisons of frameworks at the implant or abutment level are not available, and knowledge of the clinical function of cobalt-chromium (Co-Cr) alloy frameworks is limited. Primarily, the aim of this study was to compare the 5-year clinical performance of frameworks with or without abutment connections to implants. Secondly, the outcomes of prostheses made from Co-Cr alloy with porcelain veneers to those made of commercially pure titanium (CP Ti) with acrylic veneers were compared. The test groups comprised patients treated with screw-retained fixed prostheses made at the implant level according to the Cresco method in either dental porcelain-veneered Co-Cr alloy (n = 15) or acrylic-veneered CP Ti (n = 25). A control group of 40 randomly selected patients were provided with prostheses made at the standard abutment level in CP Ti with acrylic veneers. For all patients, clinical and radiologic 5-year data were retrospectively collected and evaluated. Five-year implant cumulative survival rates (CSRs) were 98.6% and 97.6% for test and control groups, respectively (P > .05). No major differences in bone level were demonstrated between the groups after 5 years (P > .05). Significantly more complications occurred in the test groups compared to the control group (P level prostheses made of porcelain-veneered Co-Cr or acrylic-veneered CP Ti seem comparable to acrylic-veneered titanium prostheses made at the standard abutment level regarding implant CSR and bone levels. However, more complications were registered in implant-level prostheses compared to the standard abutment-level prostheses.

  15. Visual field measurement with motion sensitivity screening test

    African Journals Online (AJOL)

    has been shown that early ocular lesions which manifest as visual field defects or ... easy-to-understand computer perimetry that could be useful in monitoring visual field changes in onchocer- .... education with the equivalent of ordinary level.

  16. 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

  17. 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.

  18. 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.

  19. 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 ...

  20. 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 ...

  1. Experimental test of contemporary mathematical models of visual letter recognition.

    Science.gov (United States)

    Townsend, J T; Ashby, F G

    1982-12-01

    A letter confusion experiment that used brief durations manipulated payoffs across the four stimulus letters, which were composed of line segments equal in length. The observers were required to report the features they perceived as well as to give a letter response. The early feature-sampling process is separated from the later letter-decision process in the substantive feature models, and predictions are thus obtained for the frequencies of feature report as well as letter report. Four substantive visual feature-processing models are developed and tested against one another and against three models of a more descriptive nature. The substantive models predict the decisional letter report phase much better than they do the feature-sampling phase, but the best overall 4 X 4 letter confusion matrix fits are obtained with one of the descriptive models, the similarity choice model. The present and other recent results suggest that the assumption that features are sampled in a stochastically independent manner may not be generally valid. The traditional high-threshold conceptualization of feature sampling is also falsified by the frequent reporting by observers of features not contained in the stimulus letter.

  2. 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

  3. 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.

  4. [Posturographic study of total prostheses in the leg. Apropos of 88 patients examined].

    Science.gov (United States)

    Lord, G; Gentaz, R; Gagey, P M; Baron, J B

    1976-01-01

    By suppressing certain articular sensory receptors, the reconstructive surgery of joints using total prostheses modifies tonic postural activity and, by this means, alters the regulation of balance in the subjects of operation. This doubtless explains certain discrepancies between the apparently excellent results in respect of joint movement and muscle strength and poor utilisation of the joint in every day life (instability, use of sticks or failure to use the joint in walking). Drawing on the experience and basic work of specialists in posture, the authors have undertaken a study of tonic postural activity in patients who had received a total prosthesis in the lower limb, both from the clinical aspect and by graphic measurement using an electronic apparatus, the statokinesiometer. Fourteen normal subjects were tested to calibrate the apparatus and 8 patients suffering from established osteoarthritis of the hip were studied as controls. Analysis of tonic postural activity was made in 66 patients who had received total prostheses in the lower limb. The results showed significant disturbance in balance in ankle prostheses, minimal disturbance in knee prostheses and not significant disturbance in hip prostheses. Certain therapeutic implications are derived from this study.

  5. 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.

  6. Stress analysis in oral obturator prostheses, part II: photoelastic imaging

    Science.gov (United States)

    Pesqueira, Aldiéris Alves; Goiato, Marcelo Coelho; da Silva, Emily Vivianne Freitas; Haddad, Marcela Filié; Moreno, Amália; Zahoui, Abbas; dos Santos, Daniela Micheline

    2014-06-01

    In part I of the study, two attachment systems [O-ring; bar-clip (BC)] were used, and the system with three individualized O-rings provided the lowest stress on the implants and the support tissues. Therefore, the aim of this study was to assess the stress distribution, through the photoelastic method, on implant-retained palatal obturator prostheses associated with different attachment systems: BOC-splinted implants with a bar connected to two centrally placed O-rings, and BOD-splinted implants with a BC connected to two distally placed O-rings (cantilever). One photoelastic model of the maxilla with oral-sinus-nasal communication with three parallel implants was fabricated. Afterward, two implant-retained palatal obturator prostheses with the two attachment systems described above were constructed. Each assembly was positioned in a circular polariscope and a 100-N axial load was applied in three different regions with implants by using a universal testing machine. The results were obtained through photograph record analysis of stress. The BOD system exhibited the highest stress concentration, followed by the BOC system. The O-ring, centrally placed on the bar, allows higher mobility of the prostheses and homogeneously distributes the stress to the region of the alveolar ridge and implants. It can be concluded that the use of implants with O-rings, isolated or connected with a bar, to rehabilitate maxillectomized patients allows higher prosthesis mobility and homogeneously distributes the stress to the alveolar ridge region, which may result in greater chewing stress distribution to implants and bone tissue. The clinical implication of the augmented bone support loss after maxillectomy is the increase of stress in the attachment systems and, consequently, a higher tendency for displacement of the prosthesis.

  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. 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

  9. 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

  10. 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.

  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. Edentulous patients' knowledge of dental hygiene and care of prostheses.

    Science.gov (United States)

    de Castellucci Barbosa, Luciano; Ferreira, Manoela Rejane Maia; de Carvalho Calabrich, Carolina Freire; Viana, Aline Cavalcanti; de Lemos, Maria Catarina Lavigne; Lauria, Roberta Andrade

    2008-06-01

    The aim of this study was to analyse denture users' oral care habits with regard to the use of their prostheses. Rehabilitative treatment is only successful when patients are motivated and aware of correct prosthesis use and hygiene. Questionnaires were distributed to 150 complete denture users at the Federal University of Bahia School of Dentistry, the Esmeralda Natividade Health Center, the Bahian Science Development Foundation and a Salvador nursing home. The questionnaire included information on gender, age, length of prosthesis use, cleaning methods and materials, etc. The data were analysed using EpiInfo version 6 software. The chi-squared test was used for statistical analysis, with a significance level of 5%. Questionnaire results showed that 78% of the subjects, with an average age of 67.3 years, had used the same complete denture for over 5 years. 64% slept with their prostheses and 44% removed them from the mouth only for cleaning. None of the patients interviewed knew anything about brushes designed specifically for complete dentures. 37.3% had a restricted diet and 44% believed that a complete denture would last for more than 10 years. Within the limitations of this study, it was concluded that the edentulous patients surveyed had limited awareness of prosthetic hygiene and long-term oral care despite extended periods of denture use.

  14. 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.

  15. 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…

  16. 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…

  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

    2010-11-01

    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

  18. [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.

  19. 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.

  20. 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.

  1. Normal Threshold Size of Stimuli in Children Using a Game-Based Visual Field Test.

    Science.gov (United States)

    Wang, Yanfang; Ali, Zaria; Subramani, Siddharth; Biswas, Susmito; Fenerty, Cecilia; Henson, David B; Aslam, Tariq

    2017-06-01

    The aim of this study was to demonstrate and explore the ability of novel game-based perimetry to establish normal visual field thresholds in children. One hundred and eighteen children (aged 8.0 ± 2.8 years old) with no history of visual field loss or significant medical history were recruited. Each child had one eye tested using a game-based visual field test 'Caspar's Castle' at four retinal locations 12.7° (N = 118) from fixation. Thresholds were established repeatedly using up/down staircase algorithms with stimuli of varying diameter (luminance 20 cd/m 2 , duration 200 ms, background luminance 10 cd/m 2 ). Relationships between threshold and age were determined along with measures of intra- and intersubject variability. The Game-based visual field test was able to establish threshold estimates in the full range of children tested. Threshold size reduced with increasing age in children. Intrasubject variability and intersubject variability were inversely related to age in children. Normal visual field thresholds were established for specific locations in children using a novel game-based visual field test. These could be used as a foundation for developing a game-based perimetry screening test for children.

  2. 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…

  3. 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)

  4. 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.

  5. 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.

  6. 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...

  7. 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.

  8. Installation and Testing of a Jorin Visual Process Analyzer

    International Nuclear Information System (INIS)

    Christensen, Kristi M.

    2010-01-01

    The Jorin Visual Process Analyzer (ViPA) is an on-line instrument that uses video microscope imaging to detect and measure the physical characteristics of dispersed objects within a process stream or laboratory sample. Object analysis is performed by capturing an on-going sequence of single frames from the video feed and relaying the images in real time to a nearby control computer where the ViPA software then processes and transfigures the information from the images into meaningful process data. The ViPA captures and analyzes approximately 15 images per second and continuously records 17 material parameters including size, shape and optical density. The ViPA software uses the measured parameters to differentiate between different classes of objects including organic droplets, gas bubbles, and solid particles. Procurement of this instrument provides a unique capability to support predictive modeling and further understanding of mass transfer during solvent extraction processes. Organic droplet data collected using the ViPA can be used to develop dispersion profiles of the liquid-liquid mixing and disengagements sections for each type of process equipment. These profiles will provide insight into mixing dynamics and will guide the prevention of emulsion formation that leads to system losses. Additionally, the measurement capabilities of the ViPA will provide the input needed to create new two-phase Computational Fluid Dynamics (CFD) models that characterize both mixing and separation operations in the various types of equipment. These models can then be used to improve process efficiency by optimizing operation parameters for each proposed extraction cycle.

  9. Visual determinants of reduced performance on the Stroop color-word test in normal aging individuals.

    Science.gov (United States)

    van Boxtel, M P; ten Tusscher, M P; Metsemakers, J F; Willems, B; Jolles, J

    2001-10-01

    It is unknown to what extent the performance on the Stroop color-word test is affected by reduced visual function in older individuals. We tested the impact of common deficiencies in visual function (reduced distant and close acuity, reduced contrast sensitivity, and color weakness) on Stroop performance among 821 normal individuals aged 53 and older. After adjustment for age, sex, and educational level, low contrast sensitivity was associated with more time needed on card I (word naming), red/green color weakness with slower card 2 performance (color naming), and reduced distant acuity with slower performance on card 3 (interference). Half of the age-related variance in speed performance was shared with visual function. The actual impact of reduced visual function may be underestimated in this study when some of this age-related variance in Stroop performance is mediated by visual function decrements. It is suggested that reduced visual function has differential effects on Stroop performance which need to be accounted for when the Stroop test is used both in research and in clinical settings. Stroop performance measured from older individuals with unknown visual status should be interpreted with caution.

  10. 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

  11. MECHANICAL HEART-VALVE PROSTHESES - SOUND LEVEL AND RELATED COMPLAINTS

    NARCIS (Netherlands)

    LAURENS, RRP; WIT, HP; EBELS, T

    In a randomised study, we investigated the sound production of mechanical heart valve prostheses and the complaints related to this sound. The CarboMedics, Bjork-Shiley monostrut and StJude Medical prostheses were compared. A-weighted levels of the pulse-like sound produced by the prosthesis were

  12. 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

  13. 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

  14. 3D-printed upper limb prostheses : a review

    NARCIS (Netherlands)

    ten Kate, J; Smit, G.; Breedveld, P.

    2017-01-01

    Goal: This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users. Methods: A review was

  15. 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.

  16. 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.

  17. [Design and optimization of wireless power and data transmission for visual prosthesis].

    Science.gov (United States)

    Lei, Xuping; Wu, Kaijie; Zhao, Lei; Chai, Xinyu

    2013-11-01

    Boosting spatial resolution of visual prostheses is an effective method to improve implant subjects' visual perception. However, power consumption of visual implants greatly rises with the increasing number of implanted electrodes. In respond to this trend, visual prostheses need to develop high-efficiency wireless power transmission and high-speed data transmission. This paper presents a review of current research progress on wireless power and data transmission for visual prostheses, analyzes relative principles and requirement, and introduces design methods of power and data transmission.

  18. 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

  19. 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

  20. 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…

  1. 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

  2. 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”

  3. 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…

  4. [Surgical silicone prostheses in the treatment of biliary tract cancers: long prostheses or short prostheses? Results apropos of 500 cases].

    Science.gov (United States)

    Kron, B

    1992-10-01

    The interest of surgical prostheses in the palliative treatment of biliary tract cancer is well established, on the basis of their good tolerance, the more than 15 year follow up experience and the number of patients operated upon. After exeresis, they allow re-establishment of continuity, either by use of a prosthesis in Y when the right and let ducts can be dissected, or by using two prostheses, a multiperforated long prosthesis reimplanted in the duodenum and a short prosthesis reimplanted in the common bile duct without attaining the sphincter of Oddi. Of the 1000 cases treated, 500 were the object of a statistical analysis, 46 being operated upon by the author, in 60% of cases for biliary tract cancer, either primary or as an extension from the gallbladder. One-third of the patients had advanced lesions and a short survival of less than 3 months. Two-thirds a median survival of 9 months. In 10%, a radical exeresis was performed with survival of more than one year without recurrence of jaundice. Failure of treatment with persistence of jaundice was due to advanced disease for which surgery is unsatisfactory. Essential complications were premature bile leaks (5%) without serious consequences if sufficient drainage was maintained, since it stopped spontaneously, and angiocholitis (6%), the result of territory exclusion or reflux. Recurrence of jaundice was related to extension of the neoplasm to the secondary bile ducts, and to hepatic metastases. Obstruction of the prosthesis before two months was rare (6%) and was preceded by angiocholitis. In the absence of recurrence of the cancer the prosthesis can be replaced surgically without difficulty.

  5. Visual acuity testing of radiographic inspectors in nondestructive inspection. Final report

    International Nuclear Information System (INIS)

    Yonemura, G.T.

    1981-06-01

    Visual acuity tests for radiographic inspectors should be correlated with the type of tasks encountered in real world radiography. The testing procedures should be capable of assessing differences in day to day performance of a given inspector as well as the performance of one inspector relative to other inspectors. Single line targets with specific parametric values for contrast, width, and blur are recommended to provide a means for testing a radiographic inspector for visual acuity. These targets may be used for periodic tests by the employing organization or for more frequent self testing by the inspector. Statistics from the National Health Survey, procedures recommended by the NAS-NRC Committee on Vision and real world radiographs have been utilized in arriving at recommended test configurations

  6. The Role of Visual Feedback on Power Output During Intermittent Wingate Testing in Ice Hockey Players

    Directory of Open Access Journals (Sweden)

    Petr Stastny

    2018-04-01

    Full Text Available Background: Visual feedback may help elicit peak performance during different types of strength and power testing, but its effect during the anaerobic Wingate test is unexplored. Therefore, the purpose of this study was to determine the effect of visual feedback on power output during a hockey-specific intermittent Wingate test (AnWT6x6 consisting of 6 stages of 6 s intervals with a 1:1 work-to-rest ratio. Methods: Thirty elite college-aged hockey players performed the AnWT6x6 with either constant (n = 15 visual feedback during all 6 stages (CVF or restricted (n = 15 visual feedback (RVF where feedback was shown only during the 2nd through 5th stages. Results: In the first stage, there were moderate-to-large effect sizes for absolute peak power (PP output and PP relative to body mass and PP relative to fat-free mass. However, the remaining stages (2–6 displayed small or negligible effects. Conclusions: These data indicate that visual feedback may play a role in optimizing power output in a non-fatigued state (1st stage, but likely does not play a role in the presence of extreme neuromuscular fatigue (6th stage during Wingate testing. To achieve the highest peak power, coaches and researchers could provide visual feedback during Wingate testing, as it may positively influence performance in the early stages of testing, but does not result in residual fatigue or negatively affect performance during subsequent stages.

  7. 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

  8. 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.

  9. 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.

  10. Progressive recovery of osseoperception as a function of the combination of implant-supported prostheses.

    Science.gov (United States)

    Batista, Mauro; Bonachela, Wellington; Soares, Janir

    2008-06-01

    The extraction of teeth involves the elimination of extremely sensitive periodontal mechanoreceptors, which play an important role in oral sensory perception. The aim of this study was to evaluate the recovery of interocclusal sensory perception for micro-thickness in individuals with different types of implant-supported prostheses. Wearers of complete dentures (CDs) comprised the negative control group (group A, n=17). The experimental group consisted of wearers of prostheses supported by osseointegrated implants (Group B, n=29), which was subsequently divided into 4 subgroups: B(1) (n=5)--implant supported overdentures (ISO) occluding with CD; B(2) (n=6)--implant-supported fixed prostheses (ISFP) occluding with CD; B(3) (n=8)--wearers of maxillary and mandibular ISFP, and B(4) (n=10)--ISFP occluding with natural dentition (ND). Individuals with ND represented the positive control group (Group C, n=24). Aluminum foils measuring 10 microm, 24 microm, 30 microm, 50 microm, 80 microm, and 104 microm thickness were placed within the premolar area, adding up to 120 tests for each individual. The mean tactile thresholds of groups A, B1, B2, B3, B4, and C were 92 microm, 27 microm, 27 microm, 14 microm, 10 microm, and 10 microm, respectively. [Correction added after publication online 18 April 2008: in the preceding sentence 92 microm, 27 microm, 14 microm, 10 microm and 10 microm, was corrected to 92 microm, 27 microm, 27 microm, 14 microm, 10 microm and 10 microm]. The Kruskal-Wallis test revealed significant difference among groups (P<0.05). The Dunn test revealed that group A was statistically different from groups C, B(3), and B(4), and that B(1) and B(2) were statistically different from group C. Progressive recovery of osseoperception as a function of the combination of implant-supported prostheses could be observed. Moreover, ISO and/or ISFP combinations may similarly maximize the recovery of osseoperception.

  11. 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.

    2017-01-01

    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…

  12. Validity of the rey visual design test in primary and secondary school children

    NARCIS (Netherlands)

    Wilhelm, P.; van Klink, M.; van Klink, M.

    2007-01-01

    The Rey Visual Design Learning Test (Rey, 1964, cited in Spreen & Strauss, 1991, Wilhelm, 2004) assesses immediate memory span, new learning, delayed recall and recognition for nonverbal material. Two studies are presented that focused on the construct validity of the RVDLT in primary and secondary

  13. 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...

  14. Computer-aided dental prostheses construction using reverse engineering.

    Science.gov (United States)

    Solaberrieta, E; Minguez, R; Barrenetxea, L; Sierra, E; Etxaniz, O

    2014-01-01

    The implementation of computer-aided design/computer-aided manufacturing (CAD/CAM) systems with virtual articulators, which take into account the kinematics, constitutes a breakthrough in the construction of customised dental prostheses. This paper presents a multidisciplinary protocol involving CAM techniques to produce dental prostheses. This protocol includes a step-by-step procedure using innovative reverse engineering technologies to transform completely virtual design processes into customised prostheses. A special emphasis is placed on a novel method that permits a virtual location of the models. The complete workflow includes the optical scanning of the patient, the use of reverse engineering software and, if necessary, the use of rapid prototyping to produce CAD temporary prostheses.

  15. A novel apparatus for testing binocular function using the 'CyberDome' three-dimensional hemispherical visual display system.

    Science.gov (United States)

    Handa, T; Ishikawa, H; Shimizu, K; Kawamura, R; Nakayama, H; Sawada, K

    2009-11-01

    Virtual reality has recently been highlighted as a promising medium for visual presentation and entertainment. A novel apparatus for testing binocular visual function using a hemispherical visual display system, 'CyberDome', has been developed and tested. Subjects comprised 40 volunteers (mean age, 21.63 years) with corrected visual acuity of -0.08 (LogMAR) or better, and stereoacuity better than 100 s of arc on the Titmus stereo test. Subjects were able to experience visual perception like being surrounded by visual images, a feature of the 'CyberDome' hemispherical visual display system. Visual images to the right and left eyes were projected and superimposed on the dome screen, allowing test images to be seen independently by each eye using polarizing glasses. The hemispherical visual display was 1.4 m in diameter. Three test parameters were evaluated: simultaneous perception (subjective angle of strabismus), motor fusion amplitude (convergence and divergence), and stereopsis (binocular disparity at 1260, 840, and 420 s of arc). Testing was performed in volunteer subjects with normal binocular vision, and results were compared with those using a major amblyoscope. Subjective angle of strabismus and motor fusion amplitude showed a significant correlation between our test and the major amblyoscope. All subjects could perceive the stereoscopic target with a binocular disparity of 480 s of arc. Our novel apparatus using the CyberDome, a hemispherical visual display system, was able to quantitatively evaluate binocular function. This apparatus offers clinical promise in the evaluation of binocular function.

  16. 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.

  17. 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...

  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. Functional changes through the usage of 3D-printed transitional prostheses in children.

    Science.gov (United States)

    Zuniga, Jorge M; Peck, Jean L; Srivastava, Rakesh; Pierce, James E; Dudley, Drew R; Than, Nicholas A; Stergiou, Nicholas

    2017-11-08

    There is limited knowledge on the use of 3 D-printed transitional prostheses, as they relate to changes in function and strength. Therefore, the purpose of this study was to identify functional and strength changes after usage of 3 D-printed transitional prostheses for multiple weeks for children with upper-limb differences. Gross manual dexterity was assessed using the Box and Block Test and wrist strength was measured using a dynamometer. This testing was conducted before and after a period of 24 ± 2.61 weeks of using a 3 D-printed transitional prosthesis. The 11 children (five girls and six boys; 3-15 years of age) who participated in the study, were fitted with a 3 D-printed transitional partial hand (n = 9) or an arm (n = 2) prosthesis. Separate two-way repeated measures ANOVAs were performed to analyze function and strength data. There was a significant hand by time interaction for function, but not for strength. Conclusion and relevance to the study of disability and rehabilitation: The increase in manual gross dexterity suggests that the Cyborg Beast 2 3 D-printed prosthesis can be used as a transitional device to improve function in children with traumatic or congenital upper-limb differences. Implications for Rehabilitation Children's prosthetic needs are complex due to their small size, rapid growth, and psychosocial development. Advancements in computer-aided design and additive manufacturing offer the possibility of designing and printing transitional prostheses at a very low cost, but there is limited knowledge on the function of this type of devices. The use of 3D printed transitional prostheses may improve manual gross dexterity in children after several weeks of using it.

  20. 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

  1. Remote Visual Testing (RVT) for the diagnostic inspection of feedwater heaters

    International Nuclear Information System (INIS)

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

    1993-01-01

    Feedwater heaters are an important component in the overall plant heat rate, reliability, availability, performance and maintenance considerations at power stations. The ability to diagnose heater problems in-situ properly can lead to: (1) Preventative plugging of damaged, but unfailed tubes; (2) In-place repair procedures; (3) Incorporation of corrective actions into replacement designs or heater/unit operations. The benefits and limitations of Non-Destructive Testing (NDT) on feedwater heaters are briefly reviewed. All Remote Visual Testing (RVT) including borescopes, fiberscopes, videoborescopes and Closed Circuit Television (CCTV) cameras are discussed along with currently accepted formats for documentation. The benefits of a comprehensive in-place inspection involving Remote Visual Testing are discussed in relationship to its diagnostic capabilities. The results of eight post-service heater inspections are discussed along with the root cause of failure of seven unique failure mechanisms. These inspections, including FWH access, RVT tool and data analysis, are detailed. 13 figs

  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. Impact of Target Distance, Target Size, and Visual Acuity on the Video Head Impulse Test.

    Science.gov (United States)

    Judge, Paul D; Rodriguez, Amanda I; Barin, Kamran; Janky, Kristen L

    2018-05-01

    The video head impulse test (vHIT) assesses the vestibulo-ocular reflex. Few have evaluated whether environmental factors or visual acuity influence the vHIT. The purpose of this study was to evaluate the influence of target distance, target size, and visual acuity on vHIT outcomes. Thirty-eight normal controls and 8 subjects with vestibular loss (VL) participated. vHIT was completed at 3 distances and with 3 target sizes. Normal controls were subdivided on the basis of visual acuity. Corrective saccade frequency, corrective saccade amplitude, and gain were tabulated. In the normal control group, there were no significant effects of target size or visual acuity for any vHIT outcome parameters; however, gain increased as target distance decreased. The VL group demonstrated higher corrective saccade frequency and amplitude and lower gain as compared with controls. In conclusion, decreasing target distance increases gain for normal controls but not subjects with VL. Preliminarily, visual acuity does not affect vHIT outcomes.

  4. PIXE characterization of tissues surrounding metallic prostheses coated with biological glasses

    International Nuclear Information System (INIS)

    Barbotteau, Y.; Irigaray, J.L.; Moretto, Ph.

    2004-01-01

    Biological glasses can be used as coatings for metallic prostheses in order to prevent corrosion. According to their composition, these glasses have different properties. We studied, in vivo, two glasses referred to as BVA and BVH. They are used as coatings of Ti6Al4V metallic implant. BVA glass disappears after 3 months of implantation and is replaced by bone. Prostheses initially coated by this glass have a larger osseous contact perimeter compared to the uncoated prostheses. This ensures a better anchoring of the implant and limits the micro-motions which cause wear debris. BVH glass keeps a constant composition during implantation and it is used like a layer which isolates metal implant from biological environment. In order to characterize the bony environment surrounding implants, we have used PIXE and RBS methods. This paper shows results of the behavior of bony tissue under micro-beam, the quality tests of new bone which replaces the BVA glass coating and the evaluation of corrosion effects. Titanium release in bony tissues begins when the metal surface of the prosthesis is exposed to biological fluids. After a few months of implantation, the titanium contamination is stabilized and remains localized within the first tens of micrometers of surrounding bone

  5. 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.

  6. 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

  7. 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.

  8. Paired-pulse flash-visual evoked potentials: new methods revive an old test.

    Science.gov (United States)

    Cantello, Roberto; Strigaro, Gionata; Prandi, Paolo; Varrasi, Claudia; Mula, Marco; Monaco, Francesco

    2011-08-01

    We aimed at reviving with modern technology the paired flash-visual evoked potential (F-VEP) testing of the visual system excitability. In the 1960s, methodological problems hindered this test, which was expected to provide important physiologic information. We studied 22 consenting healthy subjects (10 men). We recorded F-VEPs from electrodes over occipital and central brain regions. We delivered single flashes, mixed at random to flash pairs at the interstimulus interval (ISI) of 333, 125, 62.5, 50, 33, and 16.5 ms, (i.e. an internal frequency (IF) of 3, 8, 16, 20, 30, and 60 Hz). Recordings were performed with the subject's eyes closed and opened. The F-VEP was split into a "main complex" and an "afterdischarge", which we analyzed statistically in relation to the eye state (closed or open) and to the changes due to paired stimulation. The eye state affected the single F-VEP size, latency and shape significantly (p<0.05). On paired stimulation, the test (second) F-VEP exhibited significant (p<0.05), ISI-dependent size changes, such as a progressive decrease for ISIs from 62.5 to 16.5 ms (IFs of 16-60 Hz), whose timing/amount varied significantly (p<0.05) according to the eye state and to the F-VEP epoch considered. Suppression of the test F-VEP was never complete, even for the shortest ISI (ISI=16.5 ms, IF=60 Hz). The eye state (closed or open) must be considered meticulously when studying F-VEPs. F-VEP changes on paired stimulation express neural inhibition within the visual system, which can be depicted as ISI-dependent curves. Modern equipment and simplified measures render this an easy test, with statistical validity, providing specific information on the excitability properties of the visual system. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  9. Pathogenic characteristics of Candida albicans isolated from oral cavities of denture wearers and cancer patients wearing oral prostheses.

    Science.gov (United States)

    Mothibe, J V; Patel, M

    2017-09-01

    Candida albicans cause opportunistic infections including oral candidiasis in immunocompromised patients. It has an ability to cause infection due to its virulence factors. This study investigated the pathogenic characteristics of C. albicans isolated from the oral cavities of healthy subjects and two vulnerable groups, denture wearers and cancer patients wearing oral prostheses. Oral rinse samples were collected and cultured for the quantitative and qualitative analysis of Candida. Twenty strains of C. albicans isolated from the healthy individuals and denture wearers and, 14 strains isolated from the cancer patients were selected and their pathogenic characteristics were measured. The results of the study groups were compared using a Scheffe test for pairwise comparison and a chi square test. Denture wearer and cancer patients with prostheses carried significantly higher number (p production were significantly higher in the strains from denture wearers. In addition, high number of isolates from the denture wearers produced phospholipase and proteinase (85% and 80% respectively) compared to the strains from normal subjects (25% and 60% respectively). Only the germ tube formation and adherence ability were significantly higher in the strains from the cancer patients with prostheses (p = 0.05 and p oral cavity and prostheses is important in the prevention of colonization of Candida and the development of oral candidiasis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 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.

  11. Visual Acuity Testing: Feedback Affects Neither Outcome nor Reproducibility, but Leaves Participants Happier.

    Science.gov (United States)

    Bach, Michael; Schäfer, Kerstin

    2016-01-01

    Assessment of visual acuity is a well standardized procedure at least for expert opinions and clinical trials. It is often recommended not giving patients feedback on the correctness of their responses. As this viewpoint has not been quantitatively examined so far, we quantitatively assessed possible effects of feedback on visual acuity testing. In 40 normal participants we presented Landolt Cs in 8 orientations using the automated Freiburg Acuity Test (FrACT, feedback was provided in 2 x 4 conditions: (A) no feedback, (B) acoustic signals indicating correctness, (C)visual indication of correct orientation, and (D) a combination of (B) and (C). After each run the participants judged comfort. Main outcome measures were absolute visual acuity (logMAR), its test-retest agreement (limits of agreement) and participants' comfort estimates on a 5-step symmetric Likert scale. Feedback influenced acuity outcome significantly (p = 0.02), but with a tiny effect size: 0.02 logMAR poorer acuity for (D) compared to (A), even weaker effects for (B) and (C). Test-retest agreement was high (limits of agreement: ± 1.0 lines) and did not depend on feedback (p>0.5). The comfort ranking clearly differed, by 2 steps on the Likert scale: the condition (A)-no feedback-was on average "slightly uncomfortable", the other three conditions were "slightly comfortable" (pFeedback affected neither reproducibility nor the acuity outcome to any relevant extent. The participants, however, reported markedly greater comfort with any kind of feedback. We conclude that systematic feedback (as implemented in FrACT) offers nothing but advantages for routine use.

  12. 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...

  13. 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

  14. 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 ...

  15. 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

  16. Low-cost, smartphone based frequency doubling technology visual field testing using virtual reality (Conference Presentation)

    Science.gov (United States)

    Alawa, Karam A.; Sayed, Mohamed; Arboleda, Alejandro; Durkee, Heather A.; Aguilar, Mariela C.; Lee, Richard K.

    2017-02-01

    Glaucoma is the leading cause of irreversible blindness worldwide. Due to its wide prevalence, effective screening tools are necessary. The purpose of this project is to design and evaluate a system that enables portable, cost effective, smartphone based visual field screening based on frequency doubling technology. The system is comprised of an Android smartphone to display frequency doubling stimuli and handle processing, a Bluetooth remote for user input, and a virtual reality headset to simulate the exam. The LG Nexus 5 smartphone and BoboVR Z3 virtual reality headset were used for their screen size and lens configuration, respectively. The system is capable of running the C-20, N-30, 24-2, and 30-2 testing patterns. Unlike the existing system, the smartphone FDT tests both eyes concurrently by showing the same background to both eyes but only displaying the stimulus to one eye at a time. Both the Humphrey Zeiss FDT and the smartphone FDT were tested on five subjects without a history of ocular disease with the C-20 testing pattern. The smartphone FDT successfully produced frequency doubling stimuli at the correct spatial and temporal frequency. Subjects could not tell which eye was being tested. All five subjects preferred the smartphone FDT to the Humphrey Zeiss FDT due to comfort and ease of use. The smartphone FDT is a low-cost, portable visual field screening device that can be used as a screening tool for glaucoma.

  17. Using the Freiburg Acuity and Contrast Test to measure visual performance in USAF personnel after PRK.

    Science.gov (United States)

    Dennis, Richard J; Beer, Jeremy M A; Baldwin, J Bruce; Ivan, Douglas J; Lorusso, Frank J; Thompson, William T

    2004-07-01

    Photorefractive keratectomy (PRK) may be an alternative to spectacle and contact lens wear for United States Air Force (USAF) aircrew and may offer some distinct advantages in operational situations. However, any residual corneal haze or scar formation from PRK could exacerbate the disabling effects of a bright glare source on a complex visual task. The USAF recently completed a longitudinal clinical evaluation of the long-term effects of PRK on visual performance, including the experiment described herein. After baseline data were collected, 20 nonflying active duty USAF personnel underwent PRK. Visual performance was then measured at 6, 12, and 24 months after PRK. Visual acuity (VA) and contrast sensitivity (CS) data were collected by using the Freiburg Acuity and Contrast Test (FrACT), with the subject viewing half of the runs through a polycarbonate windscreen. Experimental runs were completed under 3 glare conditions: no glare source and with either a broadband or a green laser (532-nm) glare annulus (luminance approximately 6090 cd/m) surrounding the Landolt C stimulus. Systematic effects of PRK on VA relative to baseline were not identified. However, VA was almost 2 full Snellen lines worse with the laser glare source in place versus the broadband glare source. A significant drop-off was observed in CS performance after PRK under conditions of no glare and broadband glare; this was the case both with and without the windscreen. As with VA, laser glare disrupted CS performance significantly and more than broadband glare did. PRK does not appear to have affected VA, but the changes in CS might represent a true decline in visual performance. The greater disruptive effects from laser versus broadband glare may be a result of increased masking from coherent spatial noise (speckle) surrounding the laser stimulus.

  18. 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

    2016-09-01

    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. The aim of this study was to test the DD hypothesis within a longitudinal time span of 2 years. A total of 670 children participated. The mean age was 4.96 years at the start of the study and 7.02 years at the end of the study. At the end of the first year of kindergarten, both visual-spatial working memory and number sense were measured by two different tasks. At the end of first grade, mathematical performance was measured with two tasks, one for math facts and one for math problems. Multiple regressions revealed that both visual working memory and symbolic number sense are predictors of mathematical performance in first grade. Symbolic number sense appears to be the strongest predictor for both math areas (math facts and math problems). Non-symbolic number sense only predicts performance in math problems. Multivariate analyses of variance showed that a combination of visual working memory and number sense deficits (NSDs) leads to the lowest performance on mathematics. Our DD hypothesis was confirmed. Both visual working memory and symbolic number sense in kindergarten are related to mathematical performance 2 years later, and a combination of visual working memory and NSDs leads to low performance in mathematical performance. © 2016 The British Psychological Society.

  19. 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

  20. Reflections on the present and future of upper limb prostheses.

    Science.gov (United States)

    Farina, Dario; Amsüss, Sebastian

    2016-01-01

    Despite progress in research and media attention on active upper limb prostheses, presently the most common commercial upper limb prosthetic devices are not fundamentally different from solutions offered almost one century ago. Limited information transfer for both control and sensory-motor integration and challenges in socket technology have been major obstacles. By analysing the present state-of-the-art and academic achievements, we provide our opinion on the future of upper limb prostheses. We believe that surgical procedures for muscle reinnervation and osseointegration will become increasingly clinically relevant; muscle electrical signals will remain the main clinical means for prosthetic control; and chronic electrode implants, first in muscles (control), then in nerves (sensory feedback), will become viable clinical solutions. After decades of suspended clinically relevant progress, it is foreseeable that a new generation of upper limb prostheses will enter the market in the near future based on such advances, thereby offering substantial clinical benefit for patients.

  1. 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

  2. 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

  3. Visual and cognitive predictors of performance on brake reaction test: Salisbury eye evaluation driving study.

    Science.gov (United States)

    Zhang, Lei; Baldwin, Kevin; Munoz, Beatriz; Munro, Cynthia; Turano, Kathleen; Hassan, Shirin; Lyketsos, Constantine; Bandeen-Roche, Karen; West, Sheila K

    2007-01-01

    Concern for driving safety has prompted research into understanding factors related to performance. Brake reaction speed (BRS), the speed with which persons react to a sudden change in driving conditions, is a measure of performance. Our aim is to determine the visual, cognitive, and physical factors predicting BRS in a population sample of 1425 older drivers. The Maryland Department of Motor Vehicles roster of persons aged 67-87 and residing in Salisbury, MD, was used for recruitment of the study population. Procedures included the following: habitual, binocular visual acuity using ETDRS charts, contrast sensitivity using a Pelli-Robson chart, visual fields assessed with a 81-point screening Humphrey field at a single intensity threshold, and a questionnaire to ascertain medical conditions. Cognitive status was assessed using a standard battery of tests for attention, memory, visuo-spatial, and scanning. BRS was assessed using a computer-driven device that measured separately the initial reaction speed (IRS) (from light change to red until removing foot from accelerator) and physical response speed (PRS) (removing foot from accelerator to full brake depression). Five trial times were averaged, and time was converted to speed. The median brake reaction time varied from 384 to 5688 milliseconds. Age, gender, and cognition predicted total BRS, a non-informative result as there are two distinct parts to the task. Once separated, decrease in IRS was associated with low scores on cognitive factors and missing points on the visual field. A decrease in PRS was associated with having three or more physical complaints related to legs and feet, and poorer vision search. Vision was not related to PRS. We have demonstrated the importance of segregating the speeds for the two tasks involved in brake reaction. Only the IRS depends on vision. Persons in good physical condition may perform poorly on brake reaction tests if their vision or cognition is compromised.

  4. 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.

  5. 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

  6. Contrast sensitivity measured by two different test methods in healthy, young adults with normal visual acuity.

    Science.gov (United States)

    Koefoed, Vilhelm F; Baste, Valborg; Roumes, Corinne; Høvding, Gunnar

    2015-03-01

    This study reports contrast sensitivity (CS) reference values obtained by two different test methods in a strictly selected population of healthy, young adults with normal uncorrected visual acuity. Based on these results, the index of contrast sensitivity (ICS) is calculated, aiming to establish ICS reference values for this population and to evaluate the possible usefulness of ICS as a tool to compare the degree of agreement between different CS test methods. Military recruits with best eye uncorrected visual acuity 0.00 LogMAR or better, normal colour vision and age 18-25 years were included in a study to record contrast sensitivity using Optec 6500 (FACT) at spatial frequencies of 1.5, 3, 6, 12 and 18 cpd in photopic and mesopic light and CSV-1000E at spatial frequencies of 3, 6, 12 and 18 cpd in photopic light. Index of contrast sensitivity was calculated based on data from the three tests, and the Bland-Altman technique was used to analyse the agreement between ICS obtained by the different test methods. A total of 180 recruits were included. Contrast sensitivity frequency data for all tests were highly skewed with a marked ceiling effect for the photopic tests. The median ICS for Optec 6500 at 85 cd/m2 was -0.15 (95% percentile 0.45), compared with -0.00 (95% percentile 1.62) for Optec at 3 cd/m2 and 0.30 (95% percentile 1.20) FOR CSV-1000E. The mean difference between ICSFACT 85 and ICSCSV was -0.43 (95% CI -0.56 to -0.30, p<0.00) with limits of agreement (LoA) within -2.10 and 1.22. The regression line on the difference of average was near to zero (R2=0.03). The results provide reference CS and ICS values in a young, adult population with normal visual acuity. The agreement between the photopic tests indicated that they may be used interchangeably. There was little agreement between the mesopic and photopic tests. The mesopic test seemed best suited to differentiate between candidates and may therefore possibly be useful for medical selection purposes.

  7. Optimization of tomotherapy treatment planning for patients with bilateral hip prostheses.

    Science.gov (United States)

    Chapman, David; Smith, Shaun; Barnett, Rob; Bauman, Glenn; Yartsev, Slav

    2014-02-04

    To determine the effect of different imaging options and the most efficient imaging strategy for treatment planning of patients with hip prostheses. The planning kilovoltage CT (kVCT) and daily megavoltage CT (MVCT) studies for three prostate cancer patients with bilateral hip prostheses were used for creating hybrid kVCT/MVCT image sets. Treatment plans were created for kVCT images alone, hybrid kVCT/MVCT images, and MVCT images alone using the same dose prescription and planning parameters. The resulting dose volume histograms were compared. The orthopedic metal artifact reduction (O-MAR) reconstruction tool for kVCT images and different MVCT options were investigated with a water tank fit with double hip prostheses. Treatment plans were created for all imaging options and calculated dose was compared with the one measured by a pin-point ion chamber. On average for three patients, the D35% for the bladder was 8% higher in plans based on MVCT images and 7% higher in plans based on hybrid images, compared to the plans based on kVCT images alone. Likewise, the D35% for the rectum was 3% higher than the kVCT based plan for both hybrid and MVCT plans. The average difference in planned D99% in the PTV compared to kVCT plans was 0.9% and 0.1% for MVCT and hybrid plans, respectively. For the water tank with hip prostheses phantom, the kVCT plan with O-MAR correction applied showed better agreement between the measured and calculated dose than the original image set, with a difference of -1.9% compared to 3.3%. The measured doses for the MVCT plans were lower than the calculated dose due to image size limitations. The best agreement was for the kVCT/MVCT hybrid plans with the difference between calculated and measured dose around 1%. MVCT image provides better visualization of patient anatomy and hybrid kVCT/MVCT study enables more accurate calculations using updated MVCT relative electron density calibration.

  8. Optimization of tomotherapy treatment planning for patients with bilateral hip prostheses

    International Nuclear Information System (INIS)

    Chapman, David; Smith, Shaun; Barnett, Rob; Bauman, Glenn; Yartsev, Slav

    2014-01-01

    To determine the effect of different imaging options and the most efficient imaging strategy for treatment planning of patients with hip prostheses. The planning kilovoltage CT (kVCT) and daily megavoltage CT (MVCT) studies for three prostate cancer patients with bilateral hip prostheses were used for creating hybrid kVCT/MVCT image sets. Treatment plans were created for kVCT images alone, hybrid kVCT/MVCT images, and MVCT images alone using the same dose prescription and planning parameters. The resulting dose volume histograms were compared. The orthopedic metal artifact reduction (O-MAR) reconstruction tool for kVCT images and different MVCT options were investigated with a water tank fit with double hip prostheses. Treatment plans were created for all imaging options and calculated dose was compared with the one measured by a pin-point ion chamber. On average for three patients, the D 35% for the bladder was 8% higher in plans based on MVCT images and 7% higher in plans based on hybrid images, compared to the plans based on kVCT images alone. Likewise, the D 35% for the rectum was 3% higher than the kVCT based plan for both hybrid and MVCT plans. The average difference in planned D99% in the PTV compared to kVCT plans was 0.9% and 0.1% for MVCT and hybrid plans, respectively. For the water tank with hip prostheses phantom, the kVCT plan with O-MAR correction applied showed better agreement between the measured and calculated dose than the original image set, with a difference of -1.9% compared to 3.3%. The measured doses for the MVCT plans were lower than the calculated dose due to image size limitations. The best agreement was for the kVCT/MVCT hybrid plans with the difference between calculated and measured dose around 1%. MVCT image provides better visualization of patient anatomy and hybrid kVCT/MVCT study enables more accurate calculations using updated MVCT relative electron density calibration

  9. 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.

  10. 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…

  11. Micronucleus test for radiation biodosimetry in mass casualty events: Evaluation of visual and automated scoring

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, Claudia, E-mail: claudia.bolognesi@istge.i [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Balia, Cristina; Roggieri, Paola [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Cardinale, Francesco [Clinical Epidemiology Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Department of Health Sciences, University of Genoa, Genoa (Italy); Bruzzi, Paolo [Clinical Epidemiology Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Sorcinelli, Francesca [Environmental Carcinogenesis Unit, National Cancer Research Institute, Largo R. Benzi 10, 16132 Genoa (Italy); Laboratory of Genetics, Histology and Molecular Biology Section, Army Medical and Veterinary, Research Center, Via Santo Stefano Rotondo 4, 00184 Roma (Italy); Lista, Florigio [Laboratory of Genetics, Histology and Molecular Biology Section, Army Medical and Veterinary, Research Center, Via Santo Stefano Rotondo 4, 00184 Roma (Italy); D' Amelio, Raffaele [Sapienza, Universita di Roma II Facolta di Medicina e Chirurgia and Ministero della Difesa, Direzione Generale Sanita Militare (Italy); Righi, Enzo [Frascati National Laboratories, National Institute of Nuclear Physics, Via Enrico Fermi 40, 00044 Frascati, Rome (Italy)

    2011-02-15

    In the case of a large-scale nuclear or radiological incidents a reliable estimate of dose is an essential tool for providing timely assessment of radiation exposure and for making life-saving medical decisions. Cytogenetics is considered as the 'gold standard' for biodosimetry. The dicentric analysis (DA) represents the most specific cytogenetic bioassay. The micronucleus test (MN) applied in interphase in peripheral lymphocytes is an alternative and simpler approach. A dose-effect calibration curve for the MN frequency in peripheral lymphocytes from 27 adult donors was established after in vitro irradiation at a dose range 0.15-8 Gy of {sup 137}Cs gamma rays (dose rate 6 Gy min{sup -1}). Dose prediction by visual scoring in a dose-blinded study (0.15-4.0 Gy) revealed a high level of accuracy (R = 0.89). The scoring of MN is time consuming and requires adequate skills and expertise. Automated image analysis is a feasible approach allowing to reduce the time and to increase the accuracy of the dose estimation decreasing the variability due to subjective evaluation. A good correlation (R = 0.705) between visual and automated scoring with visual correction was observed over the dose range 0-2 Gy. Almost perfect discrimination power for exposure to 1-2 Gy, and a satisfactory power for 0.6 Gy were detected. This threshold level can be considered sufficient for identification of sub lethally exposed individuals by automated CBMN assay.

  12. Rules infants look by: Testing the assumption of transitivity in visual salience.

    Science.gov (United States)

    Kibbe, Melissa M; Kaldy, Zsuzsa; Blaser, Erik

    2018-01-01

    What drives infants' attention in complex visual scenes? Early models of infant attention suggested that the degree to which different visual features were detectable determines their attentional priority. Here, we tested this by asking whether two targets - defined by different features, but each equally salient when evaluated independently - would drive attention equally when pitted head-to-head. In Experiment 1, we presented 6-month-old infants with an array of gabor patches in which a target region varied either in color or spatial frequency from the background. Using a forced-choice preferential-looking method, we measured how readily infants fixated the target as its featural difference from the background was parametrically increased. Then, in Experiment 2, we used these psychometric preference functions to choose values for color and spatial frequency targets that were equally salient (preferred), and pitted them against each other within the same display. We reasoned that, if salience is transitive, then the stimuli should be iso-salient and infants should therefore show no systematic preference for either stimulus. On the contrary, we found that infants consistently preferred the color-defined stimulus. This suggests that computing visual salience in more complex scenes needs to include factors above and beyond local salience values.

  13. 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.

  14. Inkjet printing lanthanide doped nanorods test paper for visual assays of nitroaromatic explosives

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Liang [Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Mei, Qingsong [Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Yang, Lei [Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Cheng; Liu, Renyong [Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Han, Mingyong, E-mail: my-han@imre.a-star.edu.sg [Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); ASTAR, Inst Mat Res and Engn, Singapore 117602 (Singapore); Zhang, Ruilong [Department of Materials Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026 (China); Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Zhang, Zhongping, E-mail: zpzhang@iim.ac.cn [Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2013-11-13

    Graphical abstract: -- Highlights: •A test paper was used for visualization of explosive 2,4,6-trinitrophenol (TNP) by the naked eye. •TNP can strongly quench the phosphorescence of NaGdF{sub 4}:Ce/Tb nanorods. •Polyethylenimine (PEI) molecules facilitate the formation of uniform NaGdF{sub 4} nanorods. •PEI molecules provide specific recognized sites for TNP by the acid–base pairing interaction. -- Abstract: The facile and sensitive strategies for detections of nitroaromatic explosives are highly desirable in many challenging environments, especially for homeland security against terrorism. Here, we inkjet printed polyethylenimine (PEI)-coated Ce, Tb co-doped NaGdF{sub 4} nanorods (NaGdF{sub 4}:Ce/Tb NRs) onto common filter paper to construct test paper for visual and instant detections of a typical explosive 2,4,6-trinitrophenol (TNP). Polyethylenimine molecules not only facilitate the formation of uniform NaGdF{sub 4} nanorods but also provide specific recognized sites for TNP by the acid–base pairing interaction. The resultant TNP bound at the surface of PEI-coated NaGdF{sub 4}:Ce/Tb NRs can strongly quench the phosphorescence with a remarkably high quenching constant by the charge transfer mechanism from NaGdF{sub 4}:Ce/Tb NRs to TNP. By printing of the probe on a piece of filter paper, trace amounts of TNP can be visually detected by the appearance of a dark color against a bright green background under a UV lamp. This test paper can detect TNP as low as 0.45 ng mm{sup −2} by the naked eye, which provides a potential application in the rapid, on-line detections of explosives.

  15. Inkjet printing lanthanide doped nanorods test paper for visual assays of nitroaromatic explosives

    International Nuclear Information System (INIS)

    Hong, Liang; Mei, Qingsong; Yang, Lei; Zhang, Cheng; Liu, Renyong; Han, Mingyong; Zhang, Ruilong; Zhang, Zhongping

    2013-01-01

    Graphical abstract: -- Highlights: •A test paper was used for visualization of explosive 2,4,6-trinitrophenol (TNP) by the naked eye. •TNP can strongly quench the phosphorescence of NaGdF 4 :Ce/Tb nanorods. •Polyethylenimine (PEI) molecules facilitate the formation of uniform NaGdF 4 nanorods. •PEI molecules provide specific recognized sites for TNP by the acid–base pairing interaction. -- Abstract: The facile and sensitive strategies for detections of nitroaromatic explosives are highly desirable in many challenging environments, especially for homeland security against terrorism. Here, we inkjet printed polyethylenimine (PEI)-coated Ce, Tb co-doped NaGdF 4 nanorods (NaGdF 4 :Ce/Tb NRs) onto common filter paper to construct test paper for visual and instant detections of a typical explosive 2,4,6-trinitrophenol (TNP). Polyethylenimine molecules not only facilitate the formation of uniform NaGdF 4 nanorods but also provide specific recognized sites for TNP by the acid–base pairing interaction. The resultant TNP bound at the surface of PEI-coated NaGdF 4 :Ce/Tb NRs can strongly quench the phosphorescence with a remarkably high quenching constant by the charge transfer mechanism from NaGdF 4 :Ce/Tb NRs to TNP. By printing of the probe on a piece of filter paper, trace amounts of TNP can be visually detected by the appearance of a dark color against a bright green background under a UV lamp. This test paper can detect TNP as low as 0.45 ng mm −2 by the naked eye, which provides a potential application in the rapid, on-line detections of explosives

  16. Scenic Vistas and the Changing Policy Landscape: Visualizing and Testing the Role of Visual Resources in Ecosystem Management

    Science.gov (United States)

    Robert G. Ribe; Edward T. Armstrong; Paul H. Gobster

    2002-01-01

    The Northwest Forest Plan applies a shift in policy to national forests in the Pacific Northwest, with implications for other public landscapes. This shift offers potentially strong scenic implications for areas that have historically emphasized clearcutting with little visual impact mitigation. These areas will now emphasize biocentric concerns and harvests formed...

  17. Experimental substantiation of a method of early diagnosis of infectivity of vascular prostheses with the help of 99mTc-leukocytes

    International Nuclear Information System (INIS)

    Zatevakhin, I.I.; Malov, G.A.; Govorunov, G.V.; Dobronravov, D.S.; Makhmudov, S.Ya.; Komrakov, V.E.

    1988-01-01

    Experiments on 9 dogs were staged for a study of a method of early diagnosis of infectivity of vascular prostheses of the abdominal aorta with the help of 99m Tc-labeled leukocytes. A sterile synthetic vascular prosthesis was used for prosthetics of the abdominal aorta in the 1st control group of animals, a prosthesis, previously infected with St. aureus, was used in the 2nd group, a sterile prosthesis with its subsequent infecting by i.v. injection of St. aureus was used in the 3rd group. The tolre of antibiotic therapy in infectivity of vascular prostheses was studied on the animals of the 3rd group. A radionuclide study with autologous 99m Tc-labeled leukocytes was conducted using the Deina-2 camera (Picker). Visualization of the prostheses was unobserved in the 1st control group; in the 2nd group the accumulation of 99m Tc-leucocytes in the zone of the prosthesis and its vizualization on the 4th-5th min. were noted; in the 3rd group the prothesis was visualized on the 10th-15th min. After antibiotic therapy in the 3rd group visualization of the prothesis was undetectable. The proposed method permitted visualization of a zone of infection in the early postoperative period, observation of the time course of infection development, and assessment of the efficacy of antibiotic therapy

  18. Habituation, Response to Novelty, and Dishabituation in Human Infants: Tests of a Dual-Process Theory of Visual Attention.

    Science.gov (United States)

    Kaplan, Peter S.; Werner, John S.

    1986-01-01

    Tests infants' dual-process performance (a process mediating response decrements called habituation and a state-dependent process mediating response increments called sensitization) on visual habituation-dishabituation tasks. (HOD)

  19. 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.

  20. Test-methods of chemical analysis with visual and scanner indication in ecoanalytical monitoring of nature reservoirs of Kirovograd region

    Directory of Open Access Journals (Sweden)

    Y. V. Bokhan

    2007-03-01

    Full Text Available The features of test analysis with visual and scanner indication for the exposure and semiquantitative determination of general pollutants and indices of water bodies’ quality are considered. Evaluation of some metrological descriptions of the known test-methods of pH determination, concentrations of the dissolved oxygen, nitrate- and phosphate-ions, ions of iron with visual and computer scanner-technologies using is offered.

  1. 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

  2. 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…

  3. 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 ...

  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. 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

  7. [The costs for different voice prostheses depending on the lifetime].

    Science.gov (United States)

    Schuldt, T; Ovari, A; Dommerich, S

    2013-06-01

    Voice prostheses are available in different types of architecture und from different producers. Especially the ones with antifungal properties are characterized by a high pricing. The aim of this paper is to check, whether these prices are reflected by the prosthesis life time.A Benchmarking with usage of mean lifetime and prosthesis costs. Comparing Provox 1, Provox 2, Provox Vega, Provox ActiValve, ESKA-Herrmann, Blom Singer Classic, Phonax, Blom Singer Advantage.The voice prosthesis Provox 1 offers the best price-lifetime-ratio (1.0). It's 6.7-times higher than the one of the Provox ActiValve (0.15). In addition, the classic prostheses Provox 2 (0.53), Blom Singer Classic (0.54) and ESKA-Herrmann (0.72) offer a good ratio compared to Provox 1, too.The mean lifetime of the voice prostheses do not reflect the pricing. The Provox 1 offers the best ratio and should be used as a reference in pricing the prostheses. © Georg Thieme Verlag KG Stuttgart · New York.

  8. Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze

    International Nuclear Information System (INIS)

    Santos, Daniela Micheline dos; Commar, Betina Chiarelo; Rocha Bonatto, Liliane da; Freitas da Silva, Emily Vivianne; Sônego, Mariana Vilela; Rangel, Elidiane Cipriano; Pesqueira, Aldieris Alves; Goiato, Marcelo Coelho

    2017-01-01

    The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n = 20) and heat-polymerized acrylic resin (HPAR) (n = 20), Charisma (n = 20), Structur (n = 20), and Protemp (n = 20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21 days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α = 0.05) and the Student t-test (α = 0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group. - Highlights: • Polymers used in fabrication of interim prostheses were analyzed. • The influence of a chemical polishing on these polymers was analyzed.

  9. 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.

  10. Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Daniela Micheline dos, E-mail: danielamicheline@foa.unesp.br [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Univ Estadual Paulista (UNESP), José Bonifácio St., 1193, Aracatuba, São Paulo 16015-050 (Brazil); Commar, Betina Chiarelo; Rocha Bonatto, Liliane da; Freitas da Silva, Emily Vivianne; Sônego, Mariana Vilela [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Univ Estadual Paulista (UNESP), José Bonifácio St., 1193, Aracatuba, São Paulo 16015-050 (Brazil); Rangel, Elidiane Cipriano [Technological Plasma Laboratory (LaPTec), Experimental Campus of Sorocaba, Univ Estadual Paulista (UNESP), Tres de Março Av., 511, Sorocaba, Sao Paulo, 18087-180 (Brazil); Pesqueira, Aldieris Alves; Goiato, Marcelo Coelho [Department of Dental Materials and Prosthodontics, Aracatuba Dental School, Univ Estadual Paulista (UNESP), José Bonifácio St., 1193, Aracatuba, São Paulo 16015-050 (Brazil)

    2017-02-01

    The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n = 20) and heat-polymerized acrylic resin (HPAR) (n = 20), Charisma (n = 20), Structur (n = 20), and Protemp (n = 20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21 days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α = 0.05) and the Student t-test (α = 0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group. - Highlights: • Polymers used in fabrication of interim prostheses were analyzed. • The influence of a chemical polishing on these polymers was analyzed.

  11. 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....

  12. Visualizing the Bayesian 2-test case: The effect of tree diagrams on medical decision making.

    Science.gov (United States)

    Binder, Karin; Krauss, Stefan; Bruckmaier, Georg; Marienhagen, Jörg

    2018-01-01

    In medicine, diagnoses based on medical test results are probabilistic by nature. Unfortunately, cognitive illusions regarding the statistical meaning of test results are well documented among patients, medical students, and even physicians. There are two effective strategies that can foster insight into what is known as Bayesian reasoning situations: (1) translating the statistical information on the prevalence of a disease and the sensitivity and the false-alarm rate of a specific test for that disease from probabilities into natural frequencies, and (2) illustrating the statistical information with tree diagrams, for instance, or with other pictorial representation. So far, such strategies have only been empirically tested in combination for "1-test cases", where one binary hypothesis ("disease" vs. "no disease") has to be diagnosed based on one binary test result ("positive" vs. "negative"). However, in reality, often more than one medical test is conducted to derive a diagnosis. In two studies, we examined a total of 388 medical students from the University of Regensburg (Germany) with medical "2-test scenarios". Each student had to work on two problems: diagnosing breast cancer with mammography and sonography test results, and diagnosing HIV infection with the ELISA and Western Blot tests. In Study 1 (N = 190 participants), we systematically varied the presentation of statistical information ("only textual information" vs. "only tree diagram" vs. "text and tree diagram in combination"), whereas in Study 2 (N = 198 participants), we varied the kinds of tree diagrams ("complete tree" vs. "highlighted tree" vs. "pruned tree"). All versions were implemented in probability format (including probability trees) and in natural frequency format (including frequency trees). We found that natural frequency trees, especially when the question-related branches were highlighted, improved performance, but that none of the corresponding probabilistic visualizations did.

  13. Visual observations of a degraded bundle of irradiated fuel: the Phebus FPT1 test

    International Nuclear Information System (INIS)

    Barrachin, M.; Bottomley, P.D.

    1999-01-01

    The international Phebus-FP (Fission Product) project is managed by the Institut de Protection et Surete Nucleaire in collaboration with Electricite de France (EDF), the European Commission (EC), the USNRC (USA), COG (Canada), NUPEC and JAERI (Japan), KAERI (South Korea), PSI and HSK (Switzerland). It is designed to measure the source-term and to study the degradation of irradiated UO 2 fuel in conditions typical of a severe loss of coolant accident in a pressurised water reactor (PWR). In the first test (FPT0), performed in December '93, a bundle of 20 fresh fuel rods and a central Ag-In-Cd control rod underwent a short 15-day irradiation to generate fission products before testing in the Phebus reactor in Cadarache. The second test (FPT1) was performed in July '96, in the same conditions and geometry, but using irradiated fuel (-23 GWd/tU). In the FPT1 test, the bundle was heated to an estimated 3000 K over a period of 30 minutes in order to induce a substantial liquefaction of the bundle. After the test, the bundle was embedded in epoxy and cut at different levels to investigate the mechanisms of the core degradation. This paper reports the visual observations of the degraded FPT1 bundle, very preliminary interpretations about the scenario of degradation and a comparison between the behaviour of the fuel in the FPT0 and FPT1 tests. (author)

  14. 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.

  15. 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.

    2014-01-01

    Objective 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, and 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. Methods 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 to 3 years. Fractures were observed, their locations recorded, and images compared with baseline photographs of occlusal contacts. Conclusion No significant relationship exists 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. Clinical Significance This clinical study demonstrates that there is a need to evaluate occlusion differently with implant-supported prostheses than with natural tooth supported prostheses because of the absence of a periodontal ligament. Implant supported prostheses should have minimal occlusion and

  16. 3D-printed upper limb prostheses: a review.

    Science.gov (United States)

    Ten Kate, Jelle; Smit, Gerwin; Breedveld, Paul

    2017-04-01

    This paper aims to provide an overview with quantitative information of existing 3D-printed upper limb prostheses. We will identify the benefits and drawbacks of 3D-printed devices to enable improvement of current devices based on the demands of prostheses users. A review was performed using Scopus, Web of Science and websites related to 3D-printing. Quantitative information on the mechanical and kinematic specifications and 3D-printing technology used was extracted from the papers and websites. The overview (58 devices) provides the general specifications, the mechanical and kinematic specifications of the devices and information regarding the 3D-printing technology used for hands. The overview shows prostheses for all different upper limb amputation levels with different types of control and a maximum material cost of $500. A large range of various prostheses have been 3D-printed, of which the majority are used by children. Evidence with respect to the user acceptance, functionality and durability of the 3D-printed hands is lacking. Contrary to what is often claimed, 3D-printing is not necessarily cheap, e.g., injection moulding can be cheaper. Conversely, 3D-printing provides a promising possibility for individualization, e.g., personalized socket, colour, shape and size, without the need for adjusting the production machine. Implications for rehabilitation Upper limb deficiency is a condition in which a part of the upper limb is missing as a result of a congenital limb deficiency of as a result of an amputation. A prosthetic hand can restore some of the functions of a missing limb and help the user in performing activities of daily living. Using 3D-printing technology is one of the solutions to manufacture hand prostheses. This overview provides information about the general, mechanical and kinematic specifications of all the devices and it provides the information about the 3D-printing technology used to print the hands.

  17. [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.

  18. The stereognostic ability of natural dentitions versus implant-supported fixed prostheses or overdentures.

    Science.gov (United States)

    Jacobs, R; Bou Serhal, C; van Steenberghe, D

    1997-06-01

    A stereognostic ability test was performed in 60 patients. Forty patients were rehabilitated by means of osseointegrated implants. One group consisted of 20 patients with fixed prostheses on implants in both the upper and lower jaws. The other 20 patients had a maxillary denture while in the mandible an overdenture was retained by means of two implants connected by a bar. They were compared to a group of 20 subjects (controls) with a non-restored natural dentition. For the stereognostic ability test, subjects had to recognise ten different test pieces by manipulating them with two antagonistic incisor teeth, avoiding any contact with other oral structures. Both response time and percentage accuracy of recognition were evaluated. The present findings indicated that subjects with an overdenture on implants did not score significantly different from those with an implant-supported fixed prosthesis. In contrast, subjects with teeth had a significantly better stereognostic ability. The percentage of correct responses was 52% for overdentures, 56% for fixed prostheses on implants and 75% for natural dentitions. From these results, it could be concluded that the stereognostic ability is impaired in subjects rehabilitated with osseointegrated implants by about one-third to one-quarter compared to subjects with natural teeth.

  19. Basic quantitative assessment of visual performance in patients with very low vision.

    Science.gov (United States)

    Bach, Michael; Wilke, Michaela; Wilhelm, Barbara; Zrenner, Eberhart; Wilke, Robert

    2010-02-01

    A variety of approaches to developing visual prostheses are being pursued: subretinal, epiretinal, via the optic nerve, or via the visual cortex. This report presents a method of comparing their efficacy at genuinely improving visual function, starting at no light perception (NLP). A test battery (a computer program, Basic Assessment of Light and Motion [BaLM]) was developed in four basic visual dimensions: (1) light perception (light/no light), with an unstructured large-field stimulus; (2) temporal resolution, with single versus double flash discrimination; (3) localization of light, where a wedge extends from the center into four possible directions; and (4) motion, with a coarse pattern moving in one of four directions. Two- or four-alternative, forced-choice paradigms were used. The participants' responses were self-paced and delivered with a keypad. The feasibility of the BaLM was tested in 73 eyes of 51 patients with low vision. The light and time test modules discriminated between NLP and light perception (LP). The localization and motion modules showed no significant response for NLP but discriminated between LP and hand movement (HM). All four modules reached their ceilings in the acuity categories higher than HM. BaLM results systematically differed between the very-low-acuity categories NLP, LP, and HM. Light and time yielded similar results, as did localization and motion; still, for assessing the visual prostheses with differing temporal characteristics, they are not redundant. The results suggest that this simple test battery provides a quantitative assessment of visual function in the very-low-vision range from NLP to HM.

  20. 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

  1. 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.

  2. 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

  3. Efficiency and effectiveness in case of disaster: a visual damage assessment test

    Science.gov (United States)

    Ooms, Kristien; Åhlén, Julia; Seipel, Stefan

    2018-05-01

    A user study is conducted to evaluate the efficiency and effectiveness of two types of visualizations to identify damages sites in case of disaster. The test consists out 36 trials (18 for each visualisation) and in each trial an area of 1 × 1 km, located in Ghent, is displayed on a screen. This image shows the combined height information from before and after the disaster. The first visualisation, page flipping, is based on greyscale images with height information from the pre- and post-disaster situation between which users can switch manually. The second visualisation, difference image, is a result of subtracting the heights (before versus after) and assigning a blue-white-red colour ramp. In order to simulate the urgency with which the data is captured, systematic and random imperfections are introduced in the post-disaster data. All participants' mouse and key interactions are logged, which is further complemented by the registration of their eye movements. This give insights the visualizations' efficiency, effectiveness and the overall search strategies of the participants.

  4. [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

  5. 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)

  6. 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.

  7. The Zombie Plot: A Simple Graphic Method for Visualizing the Efficacy of a Diagnostic Test.

    Science.gov (United States)

    Richardson, Michael L

    2016-08-09

    One of the most important jobs of a radiologist is to pick the most appropriate imaging test for a particular clinical situation. Making a proper selection sometimes requires statistical analysis. The objective of this article is to introduce a simple graphic technique, an ROC plot that has been divided into zones of mostly bad imaging efficacy (ZOMBIE, hereafter referred to as the "zombie plot"), that transforms information about imaging efficacy from the numeric domain into the visual domain. The numeric rationale for the use of zombie plots is given, as are several examples of the clinical use of these plots. Two online calculators are described that simplify the process of producing a zombie plot.

  8. 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…

  9. 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…

  10. In vitro comparative analysis of the fit of gold alloy or commercially pure titanium implant-supported prostheses before and after electroerosion.

    Science.gov (United States)

    Sartori, Ivete Aparecida de Mattias; Ribeiro, Ricardo Faria; Francischone, Carlos Eduardo; de Mattos, Maria da Gloria Chiarello

    2004-08-01

    For implant-supported prostheses, passive fit is critical for the success of rehabilitation, especially when alternative materials are used. The purpose of this study was to compare interfacial fit of implant-supported prostheses cast in titanium to those cast in gold alloy. Five 3-unit fixed partial dentures were fabricated in gold alloy (Degudent U) as 1-piece castings, and 5 others were similarly cast in commercially pure titanium (Grade 1). The interfacial gaps between the prostheses and the abutments were evaluated with an optical microscope, before and after electroerosion. Readings were made with both screws tightened (10 N.cm torque), and with only 1 side tightened, so as to also evaluate the passive fit of the prostheses. Data were compared statistically by 2-way analysis of variance and the post hoc Tukey multiple range test (alpha=.05). Before electroerosion, the interfacial gaps for the 1-piece prostheses were significantly smaller (Pelectroerosion procedure significantly (Pelectroerosion did not present significant differences when the side opposite the tightened side was analyzed, but the gold alloy group showed better fit when the tightened side was analyzed (12.8 +/- 1.4 microm for gold alloy; 29.6 +/- 4.4 microm for titanium) and when both screws were tightened (5.4 +/- 2.3 microm for gold alloy; 16.1 +/- 5.5 microm for titanium). Cast titanium prostheses, despite showing larger interfacial gaps between the prosthesis and abutment than those obtained with gold alloy, had improved fit after being subjected to electroerosion.

  11. Visual test and colorimetric determination of gold(III with the use of indicator paper

    Directory of Open Access Journals (Sweden)

    Svetlana N. Khudyakova

    2016-08-01

    Full Text Available A visual test method has been proposed for the evaluation of the gold content. It is based on the linear dependence between the length of the colored zone on an indicator paper and gold(III concentration. Indicator paper was covered by a polymer film and was in contact with the solution tested along one edge during analysis. It was impregnated by 3-phenyl-2,6-dimercapto-1,4-thiopyrone or by precipitate of its complex with copper(II. Besides Cu(II can be replaced by the Au(III ion tested in the composition of this complex. The concentration ranges for Au(III determination were equal to 0.02−2 mg·L−1 or 4−590 mg·L−1, respectively, in the presence of excess of the transition and noble metals. It was demonstrated the effectiveness of the dynamic preconcentration of Au(III for the subsequent colorimetric determination on paper filter for the concentration range 0.005–0.3 mg·L−1 (DL 0.02 mg·L−1 by using a sample volume of 10 mL. The developed procedures were successfully utilized for the determination of gold in synthetic mixtures, in auriferous quartz (RSD < 5%, and in ore from Zyryanovsk’s mine (Kazakhstan with RSD < 8%.

  12. Multifocal electroretinogram and central visual field testing in central areolar choroidal dystrophy.

    Science.gov (United States)

    Gundogan, Fatih Cakir; Dinç, Umut Asli; Erdem, Uzeyir; Ozge, Gokhan; Sobaci, Gungor

    2010-01-01

    To study multifocal electroretinogram (mfERG) and its relation to retinal sensitivity assessed by Humphrey visual field (HVF) analysis in central areolar choroidal dystrophy (CACD). Seven eyes of 4 patients with CACD and 15 normal control subjects were examined. mfERG and central 30/2 HVF were tested for each participant. Ring analysis in mfERG was evaluated. HVF results were evaluated in 5 concentric rings in order to compare the results to concentric ring analysis in mfERG. The differences between control subjects and patients were evaluated by Mann-Whitney U test and the correlations were assessed by Spearman test. Mean Snellen acuity was 0.49+/-0.10 in patients. HVF revealed central scotoma in 6 of 7 eyes (85.7%), whereas a paracentral scotoma extending to fixation point was detected in 1 eye. The retinal sensitivities in 5 concentric rings in HVF were significantly lower (p<0.001 for ring 1 to ring 4, and p=0.017 in ring 5) in CACD patients. Similarly, CACD patients had lower P1/N1 amplitudes (p<0.05) and delayed P1/N1 implicit times (p<0.05). In CACD, in the areas of scotoma detected by HVF, mfERG values were depressed. However, both mfERG and HVF abnormalities were found outside the areas of ophthalmoscopically normal retinal areas.

  13. 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.

  14. 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

  15. 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…

  16. 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.

  17. 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

    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.

  18. 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…

  19. 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

    2011-08-01

    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.

  20. 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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

    Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with [ 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 [ 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 [ 111 In]chloride imaging is more accurate in evaluating infection in prosthesis than bone imaging

  2. Manufacturing Implant Supported Auricular Prostheses by Rapid Prototyping Techniques

    OpenAIRE

    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 disadv...

  3. Workflow Optimization for Tuning Prostheses with High Input Channel

    Science.gov (United States)

    2017-10-01

    of Specific Aim 1 by driving a commercially available two DoF wrist and single DoF hand. The high -level control system will provide analog signals...AWARD NUMBER: W81XWH-16-1-0767 TITLE: Workflow Optimization for Tuning Prostheses with High Input Channel PRINCIPAL INVESTIGATOR: Daniel Merrill...Unlimited The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department

  4. Visual field

    Science.gov (United States)

    ... your visual field. How the Test is Performed Confrontation visual field exam. This is a quick and ... to achieve this important distinction for online health information and services. Learn more about A.D.A. ...

  5. 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.

  6. ELECTROMYOGRAPHIC EVALUATION OF MASTICATION AND SWALLOWING IN ELDERLY INDIVIDUALS WITH MANDIBULAR FIXED IMPLANTSUPPORTED PROSTHESES

    Science.gov (United States)

    Berretin-Felix, Giédre; Nary, Hugo; Padovani, Carlos Roberto; Trindade, Alceu Sergio; Machado, Wellington Monteiro

    2008-01-01

    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. PMID:19089202

  7. Survival and failure modes: platform-switching for internal and external hexagon cemented fixed dental prostheses.

    Science.gov (United States)

    Anchieta, Rodolfo B; Machado, Lucas S; Hirata, Ronaldo; Coelho, Paulo G; Bonfante, Estevam A

    2016-10-01

    This study evaluated the probability of survival (reliability) of platform-switched fixed dental prostheses (FDPs) cemented on different implant-abutment connection designs. Eighty-four-three-unit FDPs (molar pontic) were cemented on abutments connected to two implants of external or internal hexagon connection. Four groups (n = 21 each) were established: external hexagon connection and regular platform (ERC); external hexagon connection and switched platform (ESC); internal hexagon and regular platform (IRC); and internal hexagon and switched platform (ISC). Prostheses were subjected to step-stress accelerated life testing in water. Weibull curves and probability of survival for a mission of 100,000 cycles at 400 N (two-sided 90% CI) were calculated. The beta values of 0.22, 0.48, 0.50, and 1.25 for groups ERC, ESC, IRC, and ISC, respectively, indicated a limited role of fatigue in damage accumulation, except for group ISC. Survival decreased for both platform-switched groups (ESC: 74%, and ISC: 59%) compared with the regular matching platform counterparts (ERC: 95%, and IRC: 98%). Characteristic strength was higher only for ERC compared with ESC, but not different between internal connections. Failures chiefly involved the abutment screw. Platform switching decreased the probability of survival of FDPs on both external and internal connections. The absence in loss of characteristic strength observed in internal hexagon connections favor their use compared with platform-switched external hexagon connections. © 2016 Eur J Oral Sci.

  8. 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.

  9. Clinical Management of Implant Prostheses in Patients with Bruxism

    Science.gov (United States)

    Komiyama, Osamu; Lobbezoo, Frank; De Laat, Antoon; Iida, Takashi; Kitagawa, Tsuyoshi; Murakami, Hiroshi; Kato, Takao; Kawara, Misao

    2012-01-01

    There is general agreement that excessive stress to the bone-implant interface may result in implant overload and failure. Early failure of the implant due to excessive loading occurs shortly after uncovering the implant. Excess load on a final restoration after successful implant integration can result in physical failure of the implant structure. Many clinicians believe that overload of dental implants is a risk factor for vertical peri-implant bone loss and/or may be detrimental for the suprastructure in implant prostheses. It has been documented that occlusal parafunction, such as, bruxism (tooth grinding and clenching) affects the outcome of implant prostheses, but there is no evidence for a causal relation between the failures and overload of dental implants. In spite of this lack of evidence, often metal restorations are preferred instead of porcelain for patients in whom bruxism is presumed on the basis of tooth wear. The purpose of this paper is to discuss the importance of the occlusal scheme used in implant restorations for implant longevity and to suggest a clinical approach and occlusal materials for implant prostheses in order to prevent complications related to bruxism. PMID:22701484

  10. Magnetic resonance imaging in patients with heart valve prostheses

    International Nuclear Information System (INIS)

    Bachmann, R.; Juengehuelsing, M.; Schicha, H.; Deutsch, H.J.; Sechtem, U.; Hilger, H.H.

    1991-01-01

    Artifical valve prostheses are often regarded as a contraindication for magnetic resonance imaging (MRI), although preliminary in vitro studies suggested, that patients with these metallic implants might safely undergo MR examination. This study reports on the experience with a group of 89 patients with 100 heart valve prostheses who were examined by spin-echo MR and gradient-echo MR. MR examination was performed in all patients without complications. The spin-echo sequence showed advantages in the depiction of anatomical structures like paravalvular abcesses. Anatomical structures adjacent to the artificial valve were clearly visivle and the metal components of the valves showes no or only small artifacts. Artifacts were accentuated when using gradient-echo sequences. Gradient-echo sequences provided valuable information regarding the presence of valvular insufficiency. Physiological valvular regurgitation was easy to differentiate from pathological paravalvular or transvalvular regurgitation. These results demonstrate that patients with artificial valve prostheses can be imaged by MR without risk and that prosthesis-induced artifacts do no interfere with image interpretation. (orig.) [de

  11. Using a colorimeter to develop an intrinsic silicone shade guide for facial prostheses.

    Science.gov (United States)

    Over, L M; Andres, C J; Moore, B K; Goodacre, C J; Muñoz, C A

    1998-12-01

    To determine if using CIE L*a*b* color measurements of white facial skin could be correlated to those of silicone shade samples that visually matched the skin. Secondly, to see if a correlation in color measurements could be achieved between the silicone shade samples and duplicated silicone samples made using a shade-guide color formula. A color booth was designed according to ASTM specifications, and painted using a Munsell Value 8 gray. A Minolta colorimeter was used to make facial skin measurements on 15 white adults. The skin color was duplicated using custom-shaded silicone samples. A 7-step wedge silicone shade guide was then fabricated, representing the commonly encountered thicknesses when fabricating facial prostheses. The silicone samples were then measured with the Minolta colorimeter. The readings were compared with the previous L*a*b* readings from the corresponding patient's skin measurements, and the relative color difference was then calculated. Silicone samples were fabricated and analyzed for three of the patients to determine if duplication of the visually matched silicone specimen was possible using the silicone color formula, and if the duplicates were visually and colorimetrically equivalent to each other. The color difference Delta E and chromaticity was calculated, and the data were analyzed using a coefficient-of-variation formula expressed by percent. A Pearson Product Moment Correlation Coefficient was performed to determine if a correlation existed between the skin and the silicone samples at the p 0), but only the 1-mm and 4-mm b* readings were very strong. Patient and silicone L*a*b* measurement results showed very little change in the a* axis, while the L* and b* measurements showed more change in their numbers, with changes in depth for all patient silicone samples. Delta E numbers indicated the lowest Delta E at the 1-mm depth and the highest Delta E at the 10-mm depth. All duplicated samples matched their original silicone samples

  12. Visualizing the origins of selfish de novo mutations in individual seminiferous tubules of human testes.

    Science.gov (United States)

    Maher, Geoffrey J; McGowan, Simon J; Giannoulatou, Eleni; Verrill, Clare; Goriely, Anne; Wilkie, Andrew O M

    2016-03-01

    De novo point mutations arise predominantly in the male germline and increase in frequency with age, but it has not previously been possible to locate specific, identifiable mutations directly within the seminiferous tubules of human testes. Using microdissection of tubules exhibiting altered expression of the spermatogonial markers MAGEA4, FGFR3, and phospho-AKT, whole genome amplification, and DNA sequencing, we establish an in situ strategy for discovery and analysis of pathogenic de novo mutations. In 14 testes from men aged 39-90 y, we identified 11 distinct gain-of-function mutations in five genes (fibroblast growth factor receptors FGFR2 and FGFR3, tyrosine phosphatase PTPN11, and RAS oncogene homologs HRAS and KRAS) from 16 of 22 tubules analyzed; all mutations have known associations with severe diseases, ranging from congenital or perinatal lethal disorders to somatically acquired cancers. These results support proposed selfish selection of spermatogonial mutations affecting growth factor receptor-RAS signaling, highlight its prevalence in older men, and enable direct visualization of the microscopic anatomy of elongated mutant clones.

  13. 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

  14. A Study to Estimate the Effectiveness of Visual Testing Training for Aviation Maintenance Management

    Science.gov (United States)

    Law, Lewis Lyle

    2007-01-01

    The Air Commerce Act of 1926 set the beginning for standards in aviation maintenance. Even after deregulation in the late l970s, maintenance standards and requirements still have not changed far from their initial criteria. After a potential candidate completes Federal Aviation Administration training prerequisites, they may test for their Airframe and Powerplant (A&P) certificate. Performing maintenance in the aviation industry for a minimum of three years, the technician may then test for their Inspection Authorization (IA). After receiving their Airframe and Powerplant certificate, a technician is said to have a license to perform. At no time within the three years to eligibility for Inspection Authorization are they required to attend higher-level inspection training. What a technician learns in the aviation maintenance industry is handed down from a seasoned technician to the new hire or is developed from lessons learned on the job. Only in Europe has the Joint Aviation Authorities (JAA) required higher-level training for their aviation maintenance technicians in order to control maintenance related accidents (Lu, 2005). Throughout the 1990s both the General Accounting Office (GAO) and the National Transportation Safety Board (NTSB) made public that the FAA is historically understaffed (GAO, 1996). In a safety recommendation the NTSB stated "The Safety Board continues to lack confidence in the FAA's commitment to provide effective quality assurance and safety oversight of the ATC system (NTSB, 1990)." The Federal Aviation Administration (FAA) has been known to be proactive in creating safer skies. With such reports you would suspect the FAA to also be proactive in developing more stringent inspection training for aviation maintenance technicians. The purpose of this study is to estimate the effectiveness of higher-level inspection training, such as Visual Testing (VT) for aviation maintenance technicians, to improve the safety of aircraft and to make

  15. 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

  16. 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.

  17. 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.

  18. Fit Analysis of Different Framework Fabrication Techniques for Implant-Supported Partial Prostheses.

    Science.gov (United States)

    Spazzin, Aloísio Oro; Bacchi, Atais; Trevisani, Alexandre; Farina, Ana Paula; Dos Santos, Mateus Bertolini

    2016-01-01

    This study evaluated the vertical misfit of implant-supported frameworks made using different techniques to obtain passive fit. Thirty three-unit fixed partial dentures were fabricated in cobalt-chromium alloy (n = 10) using three fabrication methods: one-piece casting, framework cemented on prepared abutments, and laser welding. The vertical misfit between the frameworks and the abutments was evaluated with an optical microscope using the single-screw test. Data were analyzed using one-way analysis of variance and Tukey test (α = .05). The one-piece casted frameworks presented significantly higher vertical misfit values than those found for framework cemented on prepared abutments and laser welding techniques (P Laser welding and framework cemented on prepared abutments are effective techniques to improve the adaptation of three-unit implant-supported prostheses. These techniques presented similar fit.

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

    NARCIS (Netherlands)

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

    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

  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. Visual and Phonological Similarity Effects in Verbal Immediate Serial Recall: A Test with Kanji Materials

    Science.gov (United States)

    Saito, Satoru; Logie, Robert H.; Morita, Aiko; Law, Anna

    2008-01-01

    In a series of three experiments, native speakers of Japanese performed serial ordered written recall of visually presented Japanese kanji characters that varied systematically in visual and phonological similarity. Overall effects of phonological similarity were observed for retention of serial order under silent reading in Experiments 1 and 3…

  2. Efficacy of the Amsler Grid Test in Evaluating Glaucomatous Central Visual Field Defects.

    Science.gov (United States)

    Su, Daniel; Greenberg, Andrew; Simonson, Joseph L; Teng, Christopher C; Liebmann, Jeffrey M; Ritch, Robert; Park, Sung Chul

    2016-04-01

    To investigate the efficacy of the Amsler grid test in detecting central visual field (VF) defects in glaucoma. Prospective, cross-sectional study. Patients with glaucoma with reliable Humphrey 10-2 Swedish Interactive Threshold Algorithm standard VF on the date of enrollment or within the previous 3 months. Amsler grid tests were performed for each eye and were considered "abnormal" if there was any perceived scotoma with missing or blurry grid lines within the central 10 degrees ("Amsler grid scotoma"). An abnormal 10-2 VF was defined as ≥3 adjacent points at P grid scotoma area were calculated with the 10-2 VF as the clinical reference standard. Among eyes with an abnormal 10-2 VF, regression analyses were performed between the Amsler grid scotoma area and the 10-2 VF parameters (mean deviation [MD], scotoma extent [number of test points with P grid scotoma area. A total of 106 eyes (53 patients) were included (mean ± standard deviation age, 24-2 MD and 10-2 MD = 66±12 years, -9.61±8.64 decibels [dB] and -9.75±9.00 dB, respectively). Sensitivity, specificity, and positive and negative predictive values of the Amsler grid test were 68%, 92%, 97%, and 46%, respectively. Sensitivity was 40% in eyes with 10-2 MD better than -6 dB, 58% in eyes with 10-2 MD between -12 and -6 dB, and 92% in eyes with 10-2 MD worse than -12 dB. The area under the receiver operating characteristic curve of the Amsler grid scotoma area was 0.810 (95% confidence interval, 0.723-0.880, P grid scotoma area had the strongest relationship with 10-2 MD (quadratic R(2)=0.681), followed by 10-2 scotoma extent (quadratic R(2)=0.611) and 10-2 scotoma mean depth (quadratic R(2)=0.299) (all P grid can be used to screen for moderate to severe central vision loss from glaucoma. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  3. Testing a Poisson Counter Model for Visual Identification of Briefly Presented, Mutually Confusable Single Stimuli in Pure Accuracy Tasks

    Science.gov (United States)

    Kyllingsbaek, Soren; Markussen, Bo; Bundesen, Claus

    2012-01-01

    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…

  4. 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…

  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. 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.

  7. Examining Effects of Physical Exertion on the Dynamic Visual Acuity Test in Collegiate Athletes.

    Science.gov (United States)

    Patterson, Jessie N; Murphy, Anna M; Honaker, Julie A

    2017-01-01

    Acute symptoms of dizziness and/or imbalance commonly experienced in athletes postconcussion are speculated to arise from dysfunction at multiple levels (i.e., inner ear or central vestibular system) to appropriately integrate afferent sensory information. Disruption along any pathway of the balance system can result in symptoms of dizziness, decreased postural control function (vestibulospinal reflex), and reduced vestibulo-ocular reflex function. This may also lead to decreased gaze stability with movements of the head and may account for symptoms of blurred vision or diplopia reported in almost half of athletes sustaining a concussion. Current concussion position statements include measures of postural control to examine changes to the balance system postconcussion. The Balance Error Scoring System (BESS) is a commonly used low-cost postural control measure for concussion assessment. Although this is a widely used measure for documenting balance function on both immediate (sideline) and recovery monitoring, the BESS has been shown to be affected by physical exertion. Therefore, the BESS may not be the most efficient means of examining functional changes to the balance system immediately after head injury. Dynamic Visual Acuity Test (DVAT) has been found to effectively evaluate and monitor changes to the gaze stability system postinjury. Thus, DVAT may be an additional measure in the concussion assessment battery, as well as an alternative for more immediate sideline assessment to help make objective return-to-play decisions. The aim of the study was to determine the effects of physical exertion on a clinical vestibular assessment, the DVAT, in collegiate athletes, as a first step in defining the role of this measure in the concussion assessment battery. Cross-sectional, repeated-measures design. Twenty-eight healthy collegiate athletes (20 males, 8 females; age = 20.25 ± 1.46 yr, range = 18-25 yr) volunteered to participate in the study. Participants were

  8. Assessment of health-related quality of life in Turkish patients with facial prostheses

    Directory of Open Access Journals (Sweden)

    Atay Arzu

    2013-01-01

    Full Text Available Abstract Background Facial prostheses are intended to provide a non-operative rehabilitation for patients with acquired facial defects. By improving aesthetics and quality of life (QOL, this treatment involves reintegration of the patient into family and social life. The aim of this study was to evaluate the perception of QOL in adult patients with facial prostheses and to compare this perception with that of a control group. Methods The study participants consisted of 72 patients, who were divided into three equal-sized groups according to the type of prosthesis (OP- orbital prosthesis, AP- auricular prosthesis, NP - nasal prosthesis and 24 healthy control participants without any congenital or acquired deformity of face or body. Clinical and socio-demographic data were gathered from each person’s medical chart. Participants completed the Turkish version of the World Health Organization Quality of Life Instrument, Short Form (WHOQOL-BREF. Descriptive statistics, independent sample t-tests, Pearson's chi-square test, ANOVA, ANCOVA, and Pearson correlation were used to analyse the data. Results Compared with the control participants, patients with NP scored lower on the all domains of QOL and all three patient groups had lower scores on overall QOL and its domains of physical and environmental health. Patients with OP reported significantly lower physical health scores than those with AP, while patients with NP reported significantly lower overall QOL and psychological health scores than those with AP. Female patients had lower environmental domain scores than did male patients. The patient’s age and income correlated with social relationships QOL, while the patient’s income and the age of facial prosthesis were correlated with environmental QOL. Conclusion Patients with facial prostheses had lower scores in overall QOL, physical and environmental health domains than the control participants. Socio-demographic and clinical characteristics

  9. Antibiotic cements in articular prostheses: current orthopaedic concepts.

    Science.gov (United States)

    Langlais, F; Belot, N; Ropars, M; Thomazeau, H; Lambotte, J C; Cathelineau, G

    2006-08-01

    The possibilities and limits of antibiotic cements (ACs) have been assessed by many researchers. ACs are now approved by many drug agencies, including the US Food and Drug Administration (approval in 2003), with widespread use in prophylaxis and curative treatments. Laboratory experiments have achieved satisfactory antibiotic delivery without impairing the mechanical properties of ACs. Implantation in large animals (e.g. sheep) showed an antibiotic concentration in the bone cortex four times the minimal inhibitory concentration (MIC) 6 months after implantation. Human pharmacokinetics during total hip replacement (THR) show antibiotic concentrations 20 times the MIC in drainage fluids. No toxic concentrations have been detected in blood or urine, and no allergies, toxic effects, mechanical failures or selection of resistant microorganisms have been observed. Antibioprophylaxis has been assessed in prospective studies in over 1600 cases. In data from the Scandinavian arthroplasty registers, with an exhaustive follow-up of more than 240000 THRs, infection rate was reduced by ca. 50% (0.9% compared with 1.9%). In prostheses with severe infection, use of AC increases the infection control rate from 86% to 93% when using two-stage prosthetic exchanges. In moderate infection, a similar infection control rate (86%) was achieved either by two-stage exchange without local antibiotic or by one-stage exchange with AC; however, one-stage exchange achieved better functional results at lower cost and with reduced pain and hospital stay. Therefore, AC prophylaxis is widely used in countries with prostheses registers (Northern Europe), and use of ACs as treatment for infected prostheses is often considered as the gold standard in the EU and North America. However, AC is only an adjuvant treatment, and excision of infected and devascularized tissues as well as systemic antibiotic treatment managed by a multidisciplinary team remain the main factors of infection control.

  10. 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.

  11. Setting visual pre-placement testing in a technology manufacturing environment.

    Science.gov (United States)

    Gowan, Nancy J

    2014-01-01

    Every day we use our eyes to perform activities of daily living and work. Aging changes as well as health conditions can impact an individual's visual function, making it more difficult to accurately perform work activities. Occupational therapists work closely with optometrists and employers to develop ways to accommodate for these changes so that the employee can continue to perform the work tasks. This manuscript outlines a case study of systematically developing visual demands analyses and pre-placement vision screening assessment protocols for individuals completing quality inspection positions. When the vision screening was completed, it was discovered that over 20% of the employees had visual deficits that were correctable. This screening process yielded improved quality results but also identification of previously undetected visual deficits. Further development of vision screening in the workplace is supported.

  12. Thermal hydraulic test for reactor safety system; a visualization study on flow boiling and bubble behavior

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Soon Heung; Baek, Won Pil; Ban, In Cheol [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

    2002-03-01

    The project contribute to understand and to clarify the physical mechanism of flow nucleate boiling and CHF phenomena through the visualization experiments. the results are useful in the development of the enhancement device of heat transfer and to enhance nuclear fuel safety 1. Visual experimental facility 2. Application method of visualization Technique 3. Visualization results of flow nucleate boiling regime - Overall Bubble Behavior on the Heated Surface - Bubble Behavior near CHF Condition - Identification of Flow Structure - Three-layer flow structure 4. Quantifying of bubble parameter through a digital image processing - Image Processing Techniques - Classification of objects and measurements of the size - Three dimensional surface plot with using the luminance 5. Development and estimation of a correlation between bubble diameter and flow parameter - The effect of system parameter on bubble diameter - The development of a bubble diameter correlation . 49 refs., 42 figs., 7 tabs. (Author)

  13. 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.

  14. 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.

  15. Visualization test using piping group mock up specimen for evaluation of wastage phenomena in steam generator for FBR

    International Nuclear Information System (INIS)

    Kato, Keisuke; Yoshida, Atsuro; Arae, Kunihiko; Narabayashi, Tadashi; Ohshima, Hiroyuki; Kurihara, Akikazu

    2012-01-01

    There is a need for quantitative evaluation of wastage phenomena in steam generator for FBR. We focused attention on liquid droplet impingement erosion (LDIE) in wastage phenomena and performed basic study with piping group mock up specimen for quantitative evaluation of LDIE. First, we did visualization test of high pressure and high speed jet into the water. Test section mock up the crack of heat exchanger tube and neighboring heat exchanger tubes. We did the test under the following test conditions. Upstream pressure is 0.3MPa, vapor temperature is 300K, crack width is 0.1mm, and crack length is 40mm. (crack diameter is 0.2mm) Second, we did pressure and temperature measurement test in the same test conditions as before. We evaluated jet behavior at test section by those two tests. In addition, we did two phase flow analysis of the jet with TRAC code. (author)

  16. 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.

  17. PC-PVT 2.0: An updated platform for psychomotor vigilance task testing, analysis, prediction, and visualization.

    Science.gov (United States)

    Reifman, Jaques; Kumar, Kamal; Khitrov, Maxim Y; Liu, Jianbo; Ramakrishnan, Sridhar

    2018-07-01

    The psychomotor vigilance task (PVT) has been widely used to assess the effects of sleep deprivation on human neurobehavioral performance. To facilitate research in this field, we previously developed the PC-PVT, a freely available software system analogous to the "gold-standard" PVT-192 that, in addition to allowing for simple visual reaction time (RT) tests, also allows for near real-time PVT analysis, prediction, and visualization in a personal computer (PC). Here we present the PC-PVT 2.0 for Windows 10 operating system, which has the capability to couple PVT tests of a study protocol with the study's sleep/wake and caffeine schedules, and make real-time individualized predictions of PVT performance for such schedules. We characterized the accuracy and precision of the software in measuring RT, using 44 distinct combinations of PC hardware system configurations. We found that 15 system configurations measured RTs with an average delay of less than 10 ms, an error comparable to that of the PVT-192. To achieve such small delays, the system configuration should always use a gaming mouse as the means to respond to visual stimuli. We recommend using a discrete graphical processing unit for desktop PCs and an external monitor for laptop PCs. This update integrates a study's sleep/wake and caffeine schedules with the testing software, facilitating testing and outcome visualization, and provides near-real-time individualized PVT predictions for any sleep-loss condition considering caffeine effects. The software, with its enhanced PVT analysis, visualization, and prediction capabilities, can be freely downloaded from https://pcpvt.bhsai.org. Published by Elsevier B.V.

  18. Rough surfaces of titanium and titanium alloys for implants and prostheses

    International Nuclear Information System (INIS)

    Conforto, E.; Aronsson, B.-O.; Salito, A.; Crestou, C.; Caillard, D.

    2004-01-01

    Titanium and titanium alloys for dental implants and hip prostheses were surface-treated and/or covered by metallic or ceramic rough layers after being submitted to sand blasting. The goal of these treatments is to improve the surface roughness and consequently the osteointegration, the fixation, and the stability of the implant. The microstructure of titanium and titanium alloys submitted to these treatments has been studied and correlated to their mechanical behavior. As-treated/covered and mechanically tested surfaces were characterized by scanning electron microscopy (SEM). Structural analyses performed by transmission electron microscopy (TEM), mainly in cross-section, reveal the degree of adherence and cohesion between the surface layer and the substrate (implant). We observed that, although the same convenient surface roughness was obtained with the two types of process, many characteristics as structural properties and mechanical behavior are very different

  19. 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

  20. A need for a more user-centered design in body powered prostheses

    NARCIS (Netherlands)

    Hichert, M.; Plettenburg, D.H.; Vardy, A.N.; Will, Wendy; Scheme, Erik

    2014-01-01

    Users of body powered prostheses (BPP) complain about too high operating forces, leading to pain and/or fatigue during or after prosthetic operation. In the worst case nerve and vessel damage can occur [1, 2], leading to nonuse of prostheses. Smit et al. investigated cable forces and displacements

  1. Air-flow resistances of silicone rubber voice prostheses after formation of bacterial and fungal biofilms

    NARCIS (Netherlands)

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

    Laryngectomized patients use silicone rubber voice prostheses to rehabilitate their voice. However, biofilm formation limits the lifetime of voice prostheses by causing leakage or an increased air-flow resistance and the prosthesis has to be replaced. To determine which bacterial or yeast strains,

  2. Dual jaw treatment of edentulism using implant-supported monolithic zirconia fixed prostheses.

    Science.gov (United States)

    Altarawneh, Sandra; Limmer, Bryan; Reside, Glenn J; Cooper, Lyndon

    2015-01-01

    This case report describes restoration of the edentulous maxilla and mandible with implant supported fixed prostheses using monolithic zirconia, where the incisal edges and occluding surfaces were made of monolithic zirconia. Edentulism is a debilitating condition that can be treated with either a removable or fixed dental prosthesis. The most common type of implant-supported fixed prosthesis is the metal acrylic (hybrid), with ceramo-metal prostheses being used less commonly in complete edentulism. However, both of these prostheses designs are associated with reported complications of screw loosening or fracture and chipping of acrylic resin and porcelain. Monolithic zirconia implant-supported fixed prostheses have the potential for reduction of such complications. In this case, the CAD/CAM concept was utilized in fabrication of maxillary and mandibular screw-retained implant-supported fixed prostheses using monolithic zirconia. Proper treatment planning and execution coupled with utilizing advanced technologies contributes to highly esthetic results. However, long-term studies are required to guarantee a satisfactory long-term outcome of this modality of treatment. This case report describes the clinical and technical procedures involved in fabrication of maxillary and mandibular implant-supported fixed prostheses using monolithic zirconia as a treatment of edentulism, and proposes the possible advantages associated with using monolithic zirconia in eliminating dissimilar interfaces in such prostheses that are accountable for the most commonly occurring technical complication for these prostheses being chipping and fracture of the veneering material. © 2015 Wiley Periodicals, Inc.

  3. 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

  4. High cable forces deteriorate pinch force control in voluntary-closing body-powered prostheses

    NARCIS (Netherlands)

    Hichert, M.; Abbink, D.A.; Kyberd, P.J.; Plettenburg, D.H.

    2017-01-01

    Background It is generally asserted that reliable and intuitive control of upper-limb prostheses requires adequate feedback of prosthetic finger positions and pinch forces applied to objects. Bodypowered prostheses (BPPs) provide the user with direct proprioceptive feedback. Currently available

  5. A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

    NARCIS (Netherlands)

    Neut, D.; Dijkstra, R. J. B.; Thompson, J. I.; Kavanagh, C.; van der Mei, H. C.; Busscher, H. J.

    2015-01-01

    A degradable, poly (lactic-co-glycolic acid) (PLGA), gentamicin-loaded prophylactic coating for hydroxyapatite (HA)-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We

  6. Testing the accuracy of timing reports in visual timing tasks with a consumer-grade digital camera.

    Science.gov (United States)

    Smyth, Rachael E; Oram Cardy, Janis; Purcell, David

    2017-06-01

    This study tested the accuracy of a visual timing task using a readily available and relatively inexpensive consumer grade digital camera. A visual inspection time task was recorded using short high-speed video clips and the timing as reported by the task's program was compared to the timing as recorded in the video clips. Discrepancies in these two timing reports were investigated further and based on display refresh rate, a decision was made whether the discrepancy was large enough to affect the results as reported by the task. In this particular study, the errors in timing were not large enough to impact the results of the study. The procedure presented in this article offers an alternative method for performing a timing test, which uses readily available hardware and can be used to test the timing in any software program on any operating system and display.

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

    Directory of Open Access Journals (Sweden)

    Kelly L. Ronald

    2017-12-01

    Full Text Available 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.

  8. 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.

  9. 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.

  10. 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.

  11. A Computer-Based Sustained Visual Attention Test for Pre-School Children: Design, Development and Psychometric Properties

    Directory of Open Access Journals (Sweden)

    Roohollah Zahedian Nasb

    2016-06-01

    Full Text Available Background: Sustained visual attention is a prerequisite for learning and memory. The early evaluation of attention in childhood is essential for their school and career success in the future. The aim of this study was to design, development and investigation of psychometric properties (content, face and convergent validity and test-retest and internal consistency reliability of the computer - based sustained visual attention test (SuVAT for healthy preschool children aged 4-6 with their special needs. Methods: This study was carried out in two stages: in the first stage computerbased SuVAT in two versions original and parallel were developed. Then the test-retest and internal consistency reliability using intra-class correlation and Cronbach’s alpha coefficients respectively were examined; Face validity was calculated through ideas gathering from 10 preschool children and content validity evaluated using CVI and CVR method and convergent validity of SuVAT with CPT was assessed using Pearson correlation. Results: The developed test showed a good content and faces validity, and also had excellent test-retest reliability. In addition, the assessment of internal consistency indicated the high internal consistency of the test (Cronbach’s alpha=0.869. SuVAT and CPT test demonstrated a positive correlation upon the convergent validity testing. Conclusion: SuVAT with good reliability and validity could be used as an acceptable sustained attention assessment in preschool children.

  12. 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.

  13. The improvement of polyethylene prostheses through radiation crosslinking

    International Nuclear Information System (INIS)

    Du Plessis, T.A.; Grobbelaar, C.J.; Marais, F.

    1977-01-01

    During the past decade, remarkable progress has been made in the utilization of high-density polyethylene (HDPE) as a material for the manufacture of prostheses used in orthopaedic operations. This polymer contributes largely to the success of total hip replacement. In the case of total knee replacement it was considered imperative that a more hard-wearing polymer should be developed if at all possible, because not only are the cold-flow characteristics of ordinary high-density polyethylene at high pressures a limiting factor, but particle formation from friction can furthermore lead to physiological side-effects which adversely affect the efficacy of joints made from this material, especially so in the case of knee-joints. Bearing in mind the excellent improvements to be obtained through the radiation crosslinking of polyethylene film, the radiation crosslinking of high-density polyethylene prostheses seemed to be a logical avenue to investigate. Experimental details are presented. Gamma radiation was used. Impact strength and tensile strength measurements were made on specimens irradiated over a dose range of 0 to 80 Mrad. The results are discussed. (U.K.)

  14. Toward Balance Recovery With Leg Prostheses Using Neuromuscular Model Control

    Science.gov (United States)

    Geyer, Hartmut

    2016-01-01

    Objective Lower limb amputees are at high risk of falling as current prosthetic legs provide only limited functionality for recovering balance after unexpected disturbances. For instance, the most established control method used on powered leg prostheses tracks local joint impedance functions without taking the global function of the leg in balance recovery into account. Here we explore an alternative control policy for powered transfemoral prostheses that considers the global leg function and is based on a neuromuscular model of human locomotion. Methods We adapt this model to describe and simulate an amputee walking with a powered prosthesis using the proposed control, and evaluate the gait robustness when confronted with rough ground and swing leg disturbances. We then implement and partially evaluate the resulting controller on a leg prosthesis prototype worn by a non-amputee user. Results In simulation, the proposed prosthesis control leads to gaits that are more robust than those obtained by the impedance control method. The initial hardware experiments with the prosthesis prototype show that the proposed control reproduces normal walking patterns qualitatively and effectively responds to disturbances in early and late swing. However, the response to mid-swing disturbances neither replicates human responses nor averts falls. Conclusions The neuromuscular model control is a promising alternative to existing prosthesis controls, although further research will need to improve on the initial implementation and determine how well these results transfer to amputee gait. Significance This work provides a potential avenue for future development of control policies that help improve amputee balance recovery. PMID:26315935

  15. 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....

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

    Science.gov (United States)

    2014-10-01

    cortex  in response  to  visual  stimuli  in  the  central  and  peripheral...defined  damage  to  the  retina,  optic  nerve,  visual   radiations  or  visual   cortex  will  be  used  to  study...tooth  to  the  portable   processor  or  also  to  a  nearby  computer.   The  optical  head  can  be

  17. Analysis of exploratory eye movements in patients with schizophrenia during visual scanning of projective tests' figures Análise dos movimentos oculares de pacientes com esquizofrenia durante a exploração visual de figuras de testes projetivos

    Directory of Open Access Journals (Sweden)

    Katerina Lukasova

    2010-01-01

    Full Text Available OBJECTIVE: Compare pattern of exploratory eye movements during visual scanning of the Rorschach and TAT test cards in people with schizophrenia and controls. METHOD: 10 participants with schizophrenia and 10 controls matched by age, schooling and intellectual level participated in the study. Severity of symptoms was evaluated with the Positive and Negative Syndrome Scale. Test cards were divided into three groups: TAT cards with scenes content, TAT cards with interaction content (TAT-faces, and Rorschach cards with abstract images. Eye movements were analyzed for: total number, duration and location of fixation; and length of saccadic movements. RESULTS: Different pattern of eye movement was found, with schizophrenia participants showing lower number of fixations but longer fixation duration in Rorschach cards and TAT-faces. The biggest difference was observed in Rorschach, followed by TAT-faces and TAT-scene cards. CONCLUSIONS: Results suggest alteration in visual exploration mechanisms possibly related to integration of abstract visual information.OBJETIVO: Comparar o padrão do movimento ocular durante a inspeção dos cartões dos testes projetivos Rorschach e TAT em pessoas com esquizofrenia e controles. MÉTODO: Participaram 10 sujeitos com esquizofrenia e 10 controles, pareados por idade, escolaridade e nível de inteligência. A severidade dos sintomas foi avaliada com a Escala das Síndromes Positiva e Negativa. Os cartões dos testes foram divididos em três grupos: figuras do TAT representando ambientes, figuras do TAT com faces humanas e figuras abstratas do teste Rorschach. Os movimentos oculares foram analisados para: número total, duração e localização das fixações e comprimento dos movimentos sacádicos. RESULTADOS: Foram encontradas diferenças no padrão do movimento ocular, e pessoas com esquizofrenia apresentaram menos fixações nos cartões do teste Rorschach e TAT-faces. Maiores diferenças foram observadas nos cart

  18. 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.

  19. 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.

  20. Innovative Ultrasonic Testing (UT) of nuclear components by sampling phased array with 3D visualization of inspection results

    OpenAIRE

    Pudovikov, Sergey; Bulavinov, Andrey; Pinchuk, Roman

    2011-01-01

    Unlike other industrial branches, nuclear industry - when performing UT- is not only asking for a reliable detection, but also for an exact sizing of material defects. Under these objectives ultrasonic imaging plays an important role in practical testing of nuclear components in the data evaluation process as well as for documentation of the inspection results. 2D and 3D sound-field steering by means of phased array technology offers great opportunities for spatially correct visualization of ...

  1. Presentation of laboratory test results in patient portals: influence of interface design on risk interpretation and visual search behaviour.

    Science.gov (United States)

    Fraccaro, Paolo; Vigo, Markel; Balatsoukas, Panagiotis; van der Veer, Sabine N; Hassan, Lamiece; Williams, Richard; Wood, Grahame; Sinha, Smeeta; Buchan, Iain; Peek, Niels

    2018-02-12

    Patient portals are considered valuable instruments for self-management of long term conditions, however, there are concerns over how patients might interpret and act on the clinical information they access. We hypothesized that visual cues improve patients' abilities to correctly interpret laboratory test results presented through patient portals. We also assessed, by applying eye-tracking methods, the relationship between risk interpretation and visual search behaviour. We conducted a controlled study with 20 kidney transplant patients. Participants viewed three different graphical presentations in each of low, medium, and high risk clinical scenarios composed of results for 28 laboratory tests. After viewing each clinical scenario, patients were asked how they would have acted in real life if the results were their own, as a proxy of their risk interpretation. They could choose between: 1) Calling their doctor immediately (high interpreted risk); 2) Trying to arrange an appointment within the next 4 weeks (medium interpreted risk); 3) Waiting for the next appointment in 3 months (low interpreted risk). For each presentation, we assessed accuracy of patients' risk interpretation, and employed eye tracking to assess and compare visual search behaviour. Misinterpretation of risk was common, with 65% of participants underestimating the need for action across all presentations at least once. Participants found it particularly difficult to interpret medium risk clinical scenarios. Participants who consistently understood when action was needed showed a higher visual search efficiency, suggesting a better strategy to cope with information overload that helped them to focus on the laboratory tests most relevant to their condition. This study confirms patients' difficulties in interpreting laboratories test results, with many patients underestimating the need for action, even when abnormal values were highlighted or grouped together. Our findings raise patient safety

  2. 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…

  3. 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

  4. 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…

  5. 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,

  6. Swivel arm perimeter for visual field testing in different body positions.

    Science.gov (United States)

    Flammer, J; Hendrickson, P; Lietz, A; Stümpfig, D

    1993-01-01

    To investigate the influence of body position on visual field results, a 'swivel arm perimeter' was built, based on a modified Octopus 1-2-3. Here, the measuring unit was detected from the control unit and mounted on a swivel arm, allowing its movement in all directions. The first results obtained with this device have indicated that its development was worthwhile.

  7. Testing the distinctiveness of visual imagery and motor imagery in a reach paradigm.

    Science.gov (United States)

    Gabbard, Carl; Ammar, Diala; Cordova, Alberto

    2009-01-01

    We examined the distinctiveness of motor imagery (MI) and visual imagery (VI) in the context of perceived reachability. The aim was to explore the notion that the two visual modes have distinctive processing properties tied to the two-visual-system hypothesis. The experiment included an interference tactic whereby participants completed two tasks at the same time: a visual or motor-interference task combined with a MI or VI-reaching task. We expected increased error would occur when the imaged task and the interference task were matched (e.g., MI with the motor task), suggesting an association based on the assumption that the two tasks were in competition for space on the same processing pathway. Alternatively, if there were no differences, dissociation could be inferred. Significant increases in the number of errors were found when the modalities for the imaged (both MI and VI) task and the interference task were matched. Therefore, it appears that MI and VI in the context of perceived reachability recruit different processing mechanisms.

  8. 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…

  9. 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.

  10. 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 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.

  11. Development of underwater high-definition camera for the confirmation test of core configuration and visual examination of BWR fuel

    International Nuclear Information System (INIS)

    Watanabe, Masato; Tuji, Kenji; Ito, Keisuke

    2010-01-01

    The purpose of this study is to develop underwater High-Definition camera for the confirmation test of core configuration and visual examination of BWR fuels in order to reduce the time of these tests and total cost regarding to purchase and maintenance. The prototype model of the camera was developed and examined in real use condition in spent fuel pool at HAMAOKA-2 and 4. The examination showed that the ability of prototype model was either equaling or surpassing to conventional product expect for resistance to radiation. The camera supposes to be used in the dose rate condition of under about 10 Gy/h. (author)

  12. Mastication and jaw motion of partially edentulous patients are affected by different implant-based prostheses.

    Science.gov (United States)

    Gonçalves, T M S V; Campos, C H; Rodrigues Garcia, R C M

    2014-07-01

    The main goal of prosthetic treatment is to restore masticatory function. However, insufficient evidence supports the recommendation of one specific prosthetic intervention for partially edentulous patients. Function after the use of three different prostheses by the same partially edentulous subject. Mastication was assessed in 12 subjects (mean age 62.6 ± 7.8 years) after they had used removable partial dentures (RPDs), implant-supported partial dentures (IRPDs) and implant-fixed partial dentures (IFPDs). Masticatory ability (MA) was estimated by visual analogue scale questionnaire, while the mandibular chewing motion was evaluated by kinesiographic device, representing an objective measurement of masticatory function. Data were analysed by repeated-measures anova followed by Tukey-Kramer (P < 0.05). MA improved after IRPD and IFPD use (P < 0.05). Opening, closing and total cycle time duration were reduced after both IRPD and IFPD use (P < 0.05), irrespectively the implant prosthesis type. IFPDs and IRPDs restore the masticatory function of partially edentulous patients better than RPDs. © 2014 John Wiley & Sons Ltd.

  13. 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).

  14. MR imaging of 22 Charnley-Mueller total hip prostheses

    International Nuclear Information System (INIS)

    Lemmens, J.A.M.; Ruijs, J.H.J.

    1986-01-01

    To find out whether MR imaging is contraindicated in patients with metallic implants or can be a routine diagnostic procedure, MR investigations in 18 patients with 22 Charnley-Mueller total hip prostheses were performed on a 0.5 T Gyroscan S 5, Philips. No adverse reactions during or post MR investigation were encountered. The imaging of the soft tissue was superior to CT and showed less distortion. The diagnosis of loosening, by detection of demarcation lines at the interfaces was at its best in the distal part of the femoral stem prosthesis and was poor in the acetabular component and in the upper part of the stem prosthesis due to artifacts. (orig.) [de

  15. Gamma Ray Sterilization of Starr-Edwards Heart Valve Prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, J. R. P.; Alladine, M. F. [London Chest Hospital, London (United Kingdom)

    1967-09-15

    Starr-Edwards valves have normally been sterilized by exposure to ethylene oxide or by autoclaving. Patients having a prosthetic valve replacement are known to have a higher incidence of endocarditis in comparison with patients in which no prosthesis has been used. Ethylene oxide will only sterilize the surface of the valve and autoclaving has caused distortion of the polytetrafluorethylene ring. Work has been done on the effect of gamma radiation on the components of these valve prostheses and is given in detail. The bacteriological efficiency, at a total absorbed dose of 2. 5 Mrad, has been established. Thirty valves treated by this method have now been inserted and twelve patients have been examined post-operatively for a period of one to two years. All valves are working normally and there has been no evidence of blood-borne infection or malfunction of the valve. (author)

  16. Myoelectric signal processing for control of powered limb prostheses.

    Science.gov (United States)

    Parker, P; Englehart, K; Hudgins, B

    2006-12-01

    Progress in myoelectric control technology has over the years been incremental, due in part to the alternating focus of the R&D between control methodology and device hardware. The technology has over the past 50 years or so moved from single muscle control of a single prosthesis function to muscle group activity control of multifunction prostheses. Central to these changes have been developments in the means of extracting information from the myoelectric signal. This paper gives an overview of the myoelectric signal processing challenge, a brief look at the challenge from an historical perspective, the state-of-the-art in myoelectric signal processing for prosthesis control, and an indication of where this field is heading. The paper demonstrates that considerable progress has been made in providing clients with useful and reliable myoelectric communication channels, and that exciting work and developments are on the horizon.

  17. Radiological follow-up of uncemented knee prostheses. Preliminary study

    International Nuclear Information System (INIS)

    Martin Hervas, C.; Gomez Barrena, E.; Marquez Moreno, I.; Calle Yuste, F.; Ordonez Parra, J.M.

    1993-01-01

    The preliminary results of a prospective study of 40 uncemented total knee prostheses (TKP) are presented following a radiological protocol with fluoroscopic control and follow-up of over 2 years. The prosthesis-bone interface and the components alignment were assessed. Several radiological signs were studied to assess this interface with respect to the fixing of the component, but they showed little clinical correlation. Statistical significance (p<0.05, chisquare) was found only in the observation of sclerosis in areas of support for the tibital tray as a reaction of the bone. This radiological follow-up is of interest to determine the evolution of the interface and position of the implant to prevent complications (especially loosening) in patients, particularly those under 60 years old, who represent the group that can most benefit from prosthetic systems with uncemented anchorage because of their life expectation and level of activity. Author

  18. 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.

  19. 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.

  20. [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

  1. [Significance of various implantate localizations of Sparks prostheses, experimental studies in rats].

    Science.gov (United States)

    Brieler, H S; Parwaresch, R; Thiede, A

    1976-01-01

    Our investigations show that Sparks prostheses after subcutaneous implantation are suitable for vascular grafting. At the end of the organization period the connective tissue becomes strong, and after the third and fourth weeks collagenous and elastic fibers can be seen. Ten weeks after s.c. implantation, collagenous fibers predominate. After this the Sparks prostheses can be used as a vascular graft. Intraperitoneal implantation, however, shows a histologically different picture with characteristic findings: only fat cells can be observed, a strong granulation tissue with elastic and collagenous fibers is not present. After intraperitoneal implantation Sparks prostheses are therefore unsuitable for vascular grafts.

  2. International comparative evaluation of knee replacement with fixed or mobile-bearing posterior-stabilized prostheses.

    Science.gov (United States)

    Graves, Stephen; Sedrakyan, Art; Baste, Valborg; Gioe, Terence J; Namba, Robert; Martínez Cruz, Olga; Stea, Susanna; Paxton, Elizabeth; Banerjee, Samprit; Isaacs, Abby J; Robertsson, Otto

    2014-12-17

    Posterior-stabilized total knee prostheses were introduced to address instability secondary to loss of posterior cruciate ligament function, and they have either fixed or mobile bearings. Mobile bearings were developed to improve the function and longevity of total knee prostheses. In this study, the International Consortium of Orthopaedic Registries used a distributed health data network to study a large cohort of posterior-stabilized prostheses to determine if the outcome of a posterior-stabilized total knee prosthesis differs depending on whether it has a fixed or mobile-bearing design. Aggregated registry data were collected with a distributed health data network that was developed by the International Consortium of Orthopaedic Registries to reduce barriers to participation (e.g., security, proprietary, legal, and privacy issues) that have the potential to occur with the alternate centralized data warehouse approach. A distributed health data network is a decentralized model that allows secure storage and analysis of data from different registries. Each registry provided data on mobile and fixed-bearing posterior-stabilized prostheses implanted between 2001 and 2010. Only prostheses associated with primary total knee arthroplasties performed for the treatment of osteoarthritis were included. Prostheses with all types of fixation were included except for those with the rarely used reverse hybrid (cementless tibial and cemented femoral components) fixation. The use of patellar resurfacing was reported. The outcome of interest was time to first revision (for any reason). Multivariate meta-analysis was performed with linear mixed models with survival probability as the unit of analysis. This study includes 137,616 posterior-stabilized knee prostheses; 62% were in female patients, and 17.6% had a mobile bearing. The results of the fixed-effects model indicate that in the first year the mobile-bearing posterior-stabilized prostheses had a significantly higher hazard

  3. 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

  4. Testing the generality of the zoom-lens model: Evidence for visual-pathway specific effects of attended-region size on perception.

    Science.gov (United States)

    Goodhew, Stephanie C; Lawrence, Rebecca K; Edwards, Mark

    2017-05-01

    There are volumes of information available to process in visual scenes. Visual spatial attention is a critically important selection mechanism that prevents these volumes from overwhelming our visual system's limited-capacity processing resources. We were interested in understanding the effect of the size of the attended area on visual perception. The prevailing model of attended-region size across cognition, perception, and neuroscience is the zoom-lens model. This model stipulates that the magnitude of perceptual processing enhancement is inversely related to the size of the attended region, such that a narrow attended-region facilitates greater perceptual enhancement than a wider region. Yet visual processing is subserved by two major visual pathways (magnocellular and parvocellular) that operate with a degree of independence in early visual processing and encode contrasting visual information. Historically, testing of the zoom-lens has used measures of spatial acuity ideally suited to parvocellular processing. This, therefore, raises questions about the generality of the zoom-lens model to different aspects of visual perception. We found that while a narrow attended-region facilitated spatial acuity and the perception of high spatial frequency targets, it had no impact on either temporal acuity or the perception of low spatial frequency targets. This pattern also held up when targets were not presented centrally. This supports the notion that visual attended-region size has dissociable effects on magnocellular versus parvocellular mediated visual processing.

  5. 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.

  6. Fuel-coolant interaction visualization test for in-vessel corium retention external reactor vessel cooling (IVR-ERVC) condition

    Energy Technology Data Exchange (ETDEWEB)

    Na, Young Su; Hong, Seong Ho; Song, Jin Ho; Hong, Seong Wan [Severe Accident and PHWR Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-12-15

    A visualization test of the fuel-coolant interaction in the Test for Real cOrium Interaction with water (TROI) test facility was carried out. To experimentally simulate the In-Vessel corium Retention (IVR)- External Reactor Vessel Cooling (ERVC) conditions, prototypic corium was released directly into the coolant water without a free fall in a gas phase before making contact with the coolant. Corium (34.39 kg) consisting of uranium oxide and zirconium oxide with a weight ratio of 8:2 was superheated, and 22.54 kg of the 34.39 kg corium was passed through water contained in a transparent interaction vessel. An image of the corium jet behavior in the coolant was taken by a high-speed camera every millisecond. Thermocouple junctions installed in the vertical direction of the coolant were cut sequentially by the falling corium jet. It was clearly observed that the visualization image of the corium jet taken during the fuel-coolant interaction corresponded with the temperature variations in the direction of the falling melt. The corium penetrated through the coolant, and the jet leading edge velocity was 2.0 m/s. Debris smaller than 1 mm was 15% of the total weight of the debris collected after a fuel-coolant interaction test, and the mass median diameter was 2.9 mm.

  7. Fracture load of complete-arch implant-supported prostheses reinforced with nylon-silica mesh: An in vitro study.

    Science.gov (United States)

    Gonçalves, Fernanda de Cássia Papaiz; Amaral, Marina; Borges, Alexandre Luiz Souto; Gonçalves, Luiz Fernando Martins; Paes-Junior, Tarcisio José de Arruda

    2018-04-01

    Complete-arch implant-supported prostheses without a framework have a high risk of failure: a straightforward and inexpensive reinforcement material, such as nylon mesh, could improve their longevity. The purpose of this in vitro study was to evaluate a nylon-silica mesh compound on the fracture strength of acrylic resin and the fracture load of complete-arch implant-supported prostheses. Twenty-four complete mandibular arch implant-supported prostheses were divided into 2 groups according to cantilever length (molar and premolar) and subdivided into another 2 subgroups according to the presence or absence of reinforcing mesh. The specimens were submitted to a maximum load-to-fracture test in a universal testing machine, with a 100-N load cell, a 2 mm/min crosshead speed, and a spherical metal tip diameter of 4 mm at different points (molar and premolar). These were submitted to 1-way analysis of variance for repeated measurement and the post hoc Tukey multiple comparison test (α=.05). The mean maximum load ±standard deviation for the molar group was 393.4 ±95.0 N with reinforcement and 305.4 ±76.3 N without reinforcement (P=.02); and for the premolar group was 1083.3 ±283.7 N with reinforcement and 605.3 ±90.5 N without reinforcement (P=.001). Reinforcement with nylon mesh increased the mean maximum load of implant-supported complete-arch prostheses at both cantilever lengths. The cantilever to the premolar (5 mm) presented the highest maximum load values to fracture. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  8. 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…

  9. Evaluation of Visual Field Test Parameters after Artificial Tear Administration in Patients with Glaucoma and Dry Eye.

    Science.gov (United States)

    Özyol, Pelin; Özyol, Erhan; Karalezli, Aylin

    2018-01-01

    To examine the effect of a single dose of artificial tear administration on automated visual field (VF) testing in patients with glaucoma and dry eye syndrome. A total of 35 patients with primary open-angle glaucoma experienced in VF testing with symptoms of dry eye were enrolled in this study. At the first visit, standard VF testing was performed. At the second and third visits with an interval of one week, while the left eyes served as control, one drop of artificial tear was administered to each patient's right eye, and then VF testing was performed again. The reliability parameters, VF indices, number of depressed points at probability levels of pattern deviation plots, and test times were compared between visits. No significant difference was observed in any VF testing parameters of control eyes (P>0.05). In artificial tear administered eyes, significant improvement was observed in test duration, mean deviation, and the number of depressed points at probability levels (P˂0.5%, P˂1%, P˂2) of pattern deviation plots (P˂0.05). The post-hoc test revealed that artificial tear administration elicited an improvement in test duration, mean deviation, and the number of depressed points at probability levels (P˂0.5%, P˂1%, P˂2%) of pattern deviation plots from first visit to second and third visits (P˂0.01, for all comparisons). The intraclass correlation coefficient for the three VF test indices was found to be between 0.735 and 0.85 (P<0.001, for all). A single dose of artificial tear administration immediately before VF testing seems to improve test results and decrease test time.

  10. 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.

  11. 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.

  12. Effect of yogic breathing on accommodate braille version of six-letter cancellation test in students with visual impairment

    Directory of Open Access Journals (Sweden)

    Balaram Pradhan

    2018-01-01

    Full Text Available Context: Attentional processes tend to be less well developed in the visually impaired, who require special training to develop them fully. Yogic breathing which alters the patterns of respiration has been shown to enhance attention skills. Letter cancellation tests are well-established tools to measure attention and attention span. Here, a modified Braille version of the six-letter cancellation test (SLCT was used for students with visual impairment (VI. Aim: This study aimed to assess the immediate effects of Bhramari Pranayama (BhPr and breath awareness (BA on students with VI. Methods: This study was a self-as-control study held on 2 consecutive days, on 19 participants (8 males, 11 females, with a mean age of 15.89 ± 1.59 years, randomized into two groups. On the 1st day, Group 1 performed 10 min breath awareness and Group 2 performed Bhramari; on the 2nd day, practices were reversed. Assessments used a SLCT specially adapted for the visually impaired before and after each session. Results: The Braille letter cancellation test was successfully taken by 19 students. Scores significantly improved after both techniques for each student following practices on both days (P < 0.001. BhPr may have more effect on attention performance than BA as wrong scores significantly increased following BA (P < 0.05, but the increase in the score after Bhramari was not significant. Conclusions: Despite the small sample size improvement in attentional processes by both yoga breathing techniques was robust. Attentional skills were definitely enhanced. Long-term practice should be studied.

  13. Effect of Yogic Breathing on Accommodate Braille Version of Six-letter Cancellation Test in Students with Visual Impairment.

    Science.gov (United States)

    Pradhan, Balaram; Mohanty, Soubhagyalaxmi; Hankey, Alex

    2018-01-01

    Attentional processes tend to be less well developed in the visually impaired, who require special training to develop them fully. Yogic breathing which alters the patterns of respiration has been shown to enhance attention skills. Letter cancellation tests are well-established tools to measure attention and attention span. Here, a modified Braille version of the six-letter cancellation test (SLCT) was used for students with visual impairment (VI). This study aimed to assess the immediate effects of Bhramari Pranayama (BhPr) and breath awareness (BA) on students with VI. This study was a self-as-control study held on 2 consecutive days, on 19 participants (8 males, 11 females), with a mean age of 15.89 ± 1.59 years, randomized into two groups. On the 1 st day, Group 1 performed 10 min breath awareness and Group 2 performed Bhramari ; on the 2 nd day, practices were reversed. Assessments used a SLCT specially adapted for the visually impaired before and after each session. The Braille letter cancellation test was successfully taken by 19 students. Scores significantly improved after both techniques for each student following practices on both days ( P < 0.001). BhPr may have more effect on attention performance than BA as wrong scores significantly increased following BA ( P < 0.05), but the increase in the score after Bhramari was not significant. Despite the small sample size improvement in attentional processes by both yoga breathing techniques was robust. Attentional skills were definitely enhanced. Long-term practice should be studied.

  14. Use of the Dynamic Visual Acuity Test as a screener for community-dwelling older adults who fall.

    Science.gov (United States)

    Honaker, Julie A; Shepard, Neil T

    2011-01-01

    Adequate function of the peripheral vestibular system, specifically the vestibulo-ocular reflex (VOR; a network of neural connections between the peripheral vestibular system and the extraocular muscles) is essential for maintaining stable vision during head movements. Decreased visual acuity resulting from an impaired peripheral vestibular system may impede balance and postural control and place an individual at risk of falling. Therefore, sensitive measures of the vestibular system are warranted to screen for the tendency to fall, alerting clinicians to recommend further risk of falling assessment and referral to a falling risk reduction program. Dynamic Visual Acuity (DVA) testing is a computerized VOR assessment method to evaluate the peripheral vestibular system during head movements; reduced visual acuity as documented with DVA testing may be sensitive to screen for falling risk. This study examined the sensitivity and specificity of the computerized DVA test with yaw plane head movements for identifying community-dwelling adults (58-78 years) who are prone to falling. A total of 16 older adults with a history of two or more unexplained falls in the previous twelve months and 16 age and gender matched controls without a history of falls in the previous twelve months participated. Computerized DVA with horizontal head movements at a fixed velocity of 120 deg/sec was measured and compared with the Dynamic Gait Index (DGI) a gold standard gait assessment measurement for identifying falling risk. Receiver operating characteristics (ROC) curve analysis and area under the ROC curve (AUC) were used to assess the sensitivity and specificity of the computerized DVA as a screening measure for falling risk as determined by the DGI. Results suggested a link between computerized DVA and the propensity to fall; DVA in the yaw plane was found to be a sensitive (92%) and accurate screening measure when using a cutoff logMAR value of >0.25.

  15. Dual-energy CT and ceramic or titanium prostheses material reduce CT artifacts and provide superior image quality of total knee arthroplasty.

    Science.gov (United States)

    Kasparek, Maximilian F; Töpker, Michael; Lazar, Mathias; Weber, Michael; Kasparek, Michael; Mang, Thomas; Apfaltrer, Paul; Kubista, Bernd; Windhager, Reinhard; Ringl, Helmut

    2018-06-07

    . These findings support the use of dual-energy CT as a solid imaging base for clinical decision-making and the use of full-titanium or ceramic prostheses to allow for better CT visualization of the bone-prosthesis interface.

  16. Natural History of Bone Response to Hydroxyapatite-Coated Hip Prostheses Implanted in Humans

    OpenAIRE

    Frayssinet, P.; Hardy, D.; Hanker, J. S.; Giammara, B. L.

    1995-01-01

    A series of 15 autopsied femurs containing hydroxyapatite- coated (HA-coated) prostheses was analysed histologically. Their implantation time ranged from 5 days up to 3 years. The coating thickness of some prostheses and the percentage of the coating in contact with bone at different levels were evaluated using an image analysis device. After the newly formed bone tissue had became mature, several bone morphotypes were identified at the coating contact. From the proximal to the distal part of...

  17. Air STAR Beyond Visual Range UAS Description and Preliminary Test Results

    Science.gov (United States)

    Cunningham, Kevin; Cox, David E.; Foster, John V.; Riddick, Stephen E.; Laughter, Sean A.

    2016-01-01

    The NASA Airborne Subscale Transport Aircraft Research Unmanned Aerial System project's capabilities were expanded by updating the system design and concept of operations. The new remotely piloted airplane system design was flight tested to assess integrity and operational readiness of the design to perform flight research. The purpose of the system design is to improve aviation safety by providing a capability to validate, in high-risk conditions, technologies to prevent airplane loss of control. Two principal design requirements were to provide a high degree of reliability and that the new design provide a significant increase in test volume (relative to operations using the previous design). The motivation for increased test volume is to improve test efficiency and allow new test capabilities that were not possible with the previous design and concept of operations. Three successful test flights were conducted from runway 4-22 at NASA Goddard Space Flight Center's Wallops Flight Facility.

  18. 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.

  19. Registered Replication Report: Testing Disruptive Effects of Irrelevant Speech on Visual-Spatial Working Memory

    Directory of Open Access Journals (Sweden)

    Tatiana Kvetnaya

    2018-04-01

    Full Text Available A Partial Replication of “Functional Equivalence of Verbal and Spatial Information in Serial Short-Term Memory (Jones, Farrand, Stuart, & Morris, 1995; Experiment 4” The irrelevant speech effect (ISE—the phenomenon that background speech impairs serial recall of visually presented material—has been widely used for examining the structure of short-term memory. In Experiment 4, Jones, Farrand, Stuart, and Morris (1995 employed the ISE to demonstrate that impairment of performance is determined by the changing-state characteristics of the material, rather than its modality of origin. The present study directly replicated the spatial condition of Experiment 4 with 'N' = 40 German participants. In contrast to the original findings, no main effect of sound type was observed, 'F'(2, 78 = 0.81, 'p' = .450, η2'p' = .02. The absence of an ISE in the spatial domain does not support the changing state hypothesis.

  20. [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.

  1. Visual behaviour of ADHD children during an attention test : An almost forgotten variable

    NARCIS (Netherlands)

    Börger, Norbert; van der Meere, Jaap

    The goal of this study was to examine whether looking away behaviour of ADHD children interferes with their test performance. ADHD and normal children carried out two continuous performance tests (CPTs): one with a regular interstimulus interval (ISI), and the other with an irregular ISI. Children

  2. Visual Processing in Adolescents with Autism Spectrum Disorder: Evidence from Embedded Figures and Configural Superiority Tests

    Science.gov (United States)

    Dillen, Claudia; Steyaert, Jean; Op de Beeck, Hans P.; Boets, Bart

    2015-01-01

    The embedded figures test has often been used to reveal weak central coherence in individuals with autism spectrum disorder (ASD). Here, we administered a more standardized automated version of the embedded figures test in combination with the configural superiority task, to investigate the effect of contextual modulation on local feature…

  3. 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.

  4. Which visual sight skill tested and developed the interaction between central and peripheral vision case duels dribbling soccer skills

    Directory of Open Access Journals (Sweden)

    Zerf Mohammed

    2016-09-01

    Full Text Available The present paper analyses the effects of visual keep sight to test and develop the interaction between central and peripheral vision the case of duels dribbling among soccer under 17 years. Where This research aims to propose a method evaluating and coaching this skill in the absence of laboratory tests and virtual visual exercises as a way for Algerian coaches to control the progress of their players. From the principle that the team which wins the most duels has the best chance of winning the game. [1] Our research supports the hypothesis which confirms in one hand that Dynamic visual acuity is the combine between Peripheral and Central vision to have one eye on the ball and the other on the defined [2] . While some authors confirm that the Top-class football players do not watch their steps, but dribble with their heads up [3]. Whereas Previous studies confirm estimate of distance ball foot player is the strategy to master this skill [4] which requires the involvement of the commitment of peripheral vision for information and central vision to master the ball [5]. From the proof and results statistics applied in the current study, we confirm that narrow spaces require the interaction of central vision than peripheral vision. Otherwise, free spaces require peripheral vision than the central vision. Which leaves us to confirm that peripheral vision in the limited space [6] can suffer because the player needs to pay close attention to each contact with the ball [7].

  5. 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.

  6. Visual processing in patients with age-related macular degeneration performing a face detection test

    Directory of Open Access Journals (Sweden)

    Vottonen P

    2017-07-01

    Full Text Available Pasi Vottonen,1 Kai Kaarniranta,1,2 Ari Pääkkönen,3 Ina M Tarkka4 1Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland; 2Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 3Department of Clinical Neurophysiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 4Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland Purpose: People with age-related macular degeneration (AMD have difficulties in familiar face recognition and facial expression discrimination. Our aim was to evaluate the visual processing of faces in AMD patients and whether this would be improved by anti-vascular endothelial growth factor therapy. This was a prospective interventional cohort study. Patients: Twelve patients with monocular wet AMD and 6 control subjects were recruited. Face detection processes were studied using cortical event-related potentials (ERPs. Patients received 3 bevacizumab intravitreal injections to the single affected eye. At baseline and 4–6 weeks after the last injection, clinical presentation and ERPs of the face task were evaluated. Face pictures were shown as targets (16.7% among standard pictures of pixelated faces in an oddball-type paradigm. Results: Face pictures elicited well-defined electrical components in occipital and parieto-occipital cortical areas at baseline and after treatment. The face-specific N170 component was evident in all subjects with longer peak latency in patients than in controls (170±13 vs 155±14, P=0.032. Unexpectedly, an early component reflecting unintentional prediction of perceiving a face, that is, deviance-related negativity, was present in patients and controls. Visual acuity of the affected eye seemed improved in patients from logarithm of the minimum angle of resolution 0.71 (±0.33 to 0.52 (±0.39 by 119 (±23 days without accompanying significant change in face

  7. Visual effects of test drilling for natural gas in the Waddenzee and the North Sea coastal area

    International Nuclear Information System (INIS)

    Dijkstra, H.

    1996-01-01

    The potential hindrance of the view, caused by offshore platforms, has been investigated as part of the environmental impact reports for test drilling for natural gas in the North Sea area, on the island Ameland and in the Wadden Sea. The hindrance is determined by calculating the weighed numbers of inhabitants and vacationers within 10 km of 26 drilling sites, divided over 12 drilling areas. For each drilling area the preferred location was determined. The hindrance of the view is the lowest when drilling tests are carried out in the winter. Also digital photo paste-ups were made by which it can be shown how drilling installations look like in a landscape. Finally, measures are given by which the visual effects of drilling installations and burn off can be reduced. 34 figs., 33 tabs., 2 appendices, 35 refs

  8. 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.

  9. Visual processing in adolescents with autism spectrum disorders: Evidence from embedded figures and configural superiority tests

    OpenAIRE

    Dillen, Claudia; Steyaert, Jean; Op de Beeck, Hans; Boets, Bart

    2015-01-01

    The embedded figures test has often been used to reveal weak central coherence in individuals with autism spectrum disorder (ASD). Here, we administered a more standardized automated version of the embedded figures test in combination with the configural superiority task, to investigate the effect of contextual modulation on local feature detection in 23 adolescents with ASD and 26 matched typically developing controls. On both tasks both groups performed l...

  10. Test Facility Construction for Flow Visualization on Mixing Flow inside Subchannels of PWR Rod Bundle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seok; Jeon, Byong-Guk; Youn, Young-Jung; Choi, Hae-Seob; Euh, Dong-Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Flow inside rod bundles has a similarity with flow in porous media. To ensure thermal performance of a nuclear reactor, detailed information of the heat transfer and turbulent mixing flow phenomena taking place within the subchannels is required. The subchannel analysis is one of the key thermal-hydraulic calculations in the safety analysis of the nuclear reactor core. At present, subchannel computer codes are employed to simulate fuel elements of nuclear reactor cores and predict the performance of cores under normal operating and hypothetical accident conditions. The ability of these subchannels codes to predict both the flow and enthalpy distribution in fuel assemblies is very important in the design of nuclear reactors. Recently, according to the modern tend of the safety analysis for the nuclear reactor, a new component scale analysis code, named CUPID, and has been developed in KAERI. The CUPID code is based on a two-fluid and three-field model, and both the open and porous media approaches are incorporated. The PRIUS experiment has addressed many key topics related to flow behaviour in a rod bundle. These issues are related to the flow conditions inside a nuclear fuel element during normal operation of the plant or in accident scenarios. From the second half of 2016, flow visualization will be performed by using a high speed camera and image analysis technique, from which detailed information for the two-dimensional movement of single phase flow is quantified.

  11. 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.

  12. 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.

  13. Wireless technologies for closed-loop retinal prostheses

    Science.gov (United States)

    Ng, David C.; Bai, Shun; Yang, Jiawei; Tran, Nhan; Skafidas, Efstratios

    2009-12-01

    In this paper, we discuss various technologies needed to develop retinal prostheses with wireless power and data telemetry operation. In addition to the need to communicate with the implanted device, supply of power to the retinal prosthesis is especially difficult. This is because, in the implanted state, the device is not fixed in position due to constant motion of the eye. Furthermore, a retinal prosthesis incorporating a high density electrode array of more than 1000 electrodes is expected to consume approximately 45 mW of power and require 300 kbps of image and stimulation data. The front end of the wireless power and data transmission, the antenna, needs to be small compared to the size of the eye. Also, the wireless module is expected to operate in the reactive near-field region due to small separation between the transmit and receive antennas compared to their size and corresponding operating wavelength. An inductive link is studied as a means to transfer power and for data telemetry between the implant and external unit. In this work, the use of integrated circuit and microfabrication technologies for implementing inductive links is discussed. A closed-loop approach is taken to improve performance and reach optimum operation condition. Design and simulation data are presented as the basis for development of viable wireless module prototypes.

  14. 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.

  15. [Communication prostheses and behavioral alignment in hospital leaflets].

    Science.gov (United States)

    Vasconcellos-Silva, Paulo Roberto; Rivera, Francisco Javier Uribe; Rozemberg, Brani

    2003-08-01

    Review was made of publications that describe experience with printed material distributed to the lay public in hospital institutions. From the 146 leaflets examined, those aimed at professionals or disabled people, thus leaving 75 papers that illustrate the present pattern for the rationality behind the production, use and evaluation of this type of resource. In a general manner, such leaflets invest in the power of "ideal printed information" to align behavior with the hospital's biomedical agenda. The underlying rationality that permeates them perceives the "perfect information package" as one that efficiently describes its technical content for the purpose of unidirectional persuasion, is up-to-date in relation to readability scales and embellished by graphic design, and emphasizes the priorities defined by the professionals. Such "communication prostheses" should be capable of electronic validation by means of software suitable for proportioning the "doses" to the subject matter. Information as a drug, cognitivism, the lack of research on message reception and the need for communicative action for the deconstruction of systems of closed thinking within the hospital environment have been discussed.

  16. Intraocular camera for retinal prostheses: Refractive and diffractive lens systems

    Science.gov (United States)

    Hauer, Michelle Christine

    The focus of this thesis is on the design and analysis of refractive, diffractive, and hybrid refractive/diffractive lens systems for a miniaturized camera that can be surgically implanted in the crystalline lens sac and is designed to work in conjunction with current and future generation retinal prostheses. The development of such an intraocular camera (IOC) would eliminate the need for an external head-mounted or eyeglass-mounted camera. Placing the camera inside the eye would allow subjects to use their natural eye movements for foveation (attention) instead of more cumbersome head tracking, would notably aid in personal navigation and mobility, and would also be significantly more psychologically appealing from the standpoint of personal appearances. The capability for accommodation with no moving parts or feedback control is incorporated by employing camera designs that exhibit nearly infinite depth of field. Such an ultracompact optical imaging system requires a unique combination of refractive and diffractive optical elements and relaxed system constraints derived from human psychophysics. This configuration necessitates an extremely compact, short focal-length lens system with an f-number close to unity. Initially, these constraints appear highly aggressive from an optical design perspective. However, after careful analysis of the unique imaging requirements of a camera intended to work in conjunction with the relatively low pixellation levels of a retinal microstimulator array, it becomes clear that such a design is not only feasible, but could possibly be implemented with a single lens system.

  17. Implant prostheses for convertibility, stress control, esthetics, and hygiene.

    Science.gov (United States)

    Garfield, R E

    1988-07-01

    A method of connecting "fixed partial denture" prostheses to osseointegrated implant fixtures has been described. The advantages of this system of restoration for partially and fully edentulous mouths are that it is more effective in addressing the problems of (1) stress-control on abutments, (2) a back-up system for abutment failures, (3) esthetics, and (4) control of bacterial plaques around abutments. To accomplish this procedure, the application of convertible periodontal prosthesis techniques with modifications to some existing implant systems is undertaken. The disadvantages of this method seem insignificant when one considers the complexities and risks involved with the present array of implant prosthesis alternatives. Some patients and dentists might consider the necessity of the prosthesis being detachable as one disadvantage. In reality, the prosthesis can be used as a fixed restoration until the patient has fully adapted to the new proprioception and appearance. A large percentage of patients feel uncomfortable with the word "removable" because it immediately creates a perception of unsightly metallic clasp display, palatal coverage, tongue interference, and negative body image. The use of the term "detachable" coupled with the doctor's offer to perform this task for the patient "whenever necessary" will usually relieve the patient's anxiety and allow the treatment to proceed. Once neuromuscular and esthetic adaptation have occurred and the patient has accepted the prosthesis, daily detaching and home-care hygiene by the patient will follow without incident. Esthetic improvement is obvious (Fig. 3).

  18. Performance of zirconia ceramic cantilever fixed dental prostheses: 3-year results from a prospective, randomized, controlled pilot study.

    Science.gov (United States)

    Zenthöfer, Andreas; Ohlmann, Brigitte; Rammelsberg, Peter; Bömicke, Wolfgang

    2015-07-01

    Little is known about the clinical performance of ceramic cantilever fixed dental prostheses on natural teeth. The purpose of this randomized controlled pilot study was to evaluate the clinical performance of ceramic and metal ceramic cantilever fixed dental prostheses (CFDPs) after 3 years of service. Twenty-one participants were randomly allocated to 2 treatment groups. Participants in the ceramic (ZC) group (n=11) each received 1 CFDP made of yttria-stabilized, tetragonal zirconia polycrystal; the others (n=10) were fitted with a metal ceramic (MC) CFDP. All CFDPs were retained by 2 complete crown abutments and replaced 1 tooth. The clinical target variables were survival, incidence of complications, probing pocket depth (PPD), probing attachment level (PAL), plaque index (PI), gingival index (GI), and esthetic performance as rated by the participants. The United States Public Health Service (USPHS) criteria were used to evaluate chipping, retention, color, marginal integrity, and secondary caries. Descriptive statistics and nonparametric analyses were applied to the target variables in the 2 groups. The esthetic performance of the CFDPs was also visualized by using a pyramid comparison. The overall survival of the CFDPs was 100% in both groups. During the 3-year study, 6 clinically relevant complications requiring aftercare were observed among 5 participants (4 in the ZC group and 2 in the MC group). Changes in the PI, GI, PPD, and PAL of the abutment teeth were similar for both groups (P>.05). The participants regarded the esthetic performance of ZC-CFDPs and MC-CFDPs as satisfactory. Within the 3-year observation period, the clinical performance of MC-FDPs and ZC-FDPs was acceptable. More extensive research with larger sample sizes is encouraged, however, to confirm the evaluation of the survival of Y-TZP hand-veneered cantilever FPDs. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  19. Aging of monolithic zirconia dental prostheses: Protocol for a 5-year prospective clinical study using ex vivo analyses

    OpenAIRE

    Koenig, Vinciane; Wulfman, Claudine P.; Derbanne, Mathieu A.; Dupont, Nathalie M.; Le Goff, Stéphane O.; Tang, Mie-Leng; Seidel, Laurence; Dewael, Thibaut Y.; Vanheusden, Alain J.; Mainjot, Amélie K.

    2016-01-01

    Background: Recent introduction of computer-aided design/computer-aided manufacturing (CAD/CAM) monolithic zirconia dental prostheses raises the issue of material low thermal degradation (LTD), a well-known problem with zirconia hip prostheses. This phenomenon could be accentuated by masticatory mechanical stress. Until now zirconia LTD process has only been studied in vitro. This work introduces an original protocol to evaluate LTD process of monolithic zirconia prostheses in the oral enviro...

  20. Scotoma analysis of 10-2 visual field testing with a white target in screening for hydroxychloroquine retinopathy

    Directory of Open Access Journals (Sweden)

    Browning DJ

    2015-05-01

    Full Text Available David J Browning, Chong Lee Department of Ophthalmology, Charlotte Eye, Ear, Nose and Throat Associates, Charlotte, NC, USA Objective: To quantify the variability of scotomas detected by 10-2 visual field (VF testing in patients taking hydroxychloroquine without and with retinopathy.Design: Retrospective review of clinical charts and visual fields.Subjects: Twenty-one patients taking hydroxychloroquine without retinopathy, and nine patients taking hydroxychloroquine and one patient taking chloroquine with retinopathy.Methods: 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 white target over time.Main outcome measures: 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 five, interquartile range (IQR 3–8 scotoma points per VF occurred in patients without retinopathy. A median of 86%, IQR 63%–100% of these points resolve on the subsequent field. For patients with retinopathy, a median of 22%, IQR 10%–59% resolve. The median percentage of scotoma points in the zone 2–8 degrees from fixation in eyes with retinopathy was 79%, IQR 68%–85% compared to 60%, IQR 54%–75% in eyes without retinopathy (P=0.0094. Single-point scotomas were more common in eyes without than with retinopathy. Scotomas consisting of more than four contiguous scotoma points were generally indicative of retinopathy.Conclusion: Point scotomas are common and variable in 10-2 VF testing with a white target for hydroxychloroquine retinopathy in subjects without retinopathy. The annular zone 2 to 8

  1. 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…

  2. 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…

  3. 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.

  4. 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

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

    Science.gov (United States)

    Kocabeyoglu, Sibel; Uzun, Salih; Mocan, Mehmet Cem; Bozkurt, Banu; Irkec, Murat; Orhan, Mehmet

    2013-10-01

    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. 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. 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 tests in terms of MD (r = 0.352, P = 0.008) and PSD (r = 0.329, P = 0.014) was observed. 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.

  6. 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.

  7. Control of a visual keyboard using an electrocorticographic brain-computer interface.

    Science.gov (United States)

    Krusienski, Dean J; Shih, Jerry J

    2011-05-01

    Brain-computer interfaces (BCIs) are devices that enable severely disabled people to communicate and interact with their environments using their brain waves. Most studies investigating BCI in humans have used scalp EEG as the source of electrical signals and focused on motor control of prostheses or computer cursors on a screen. The authors hypothesize that the use of brain signals obtained directly from the cortical surface will more effectively control a communication/spelling task compared to scalp EEG. A total of 6 patients with medically intractable epilepsy were tested for the ability to control a visual keyboard using electrocorticographic (ECOG) signals. ECOG data collected during a P300 visual task paradigm were preprocessed and used to train a linear classifier to subsequently predict the intended target letters. The classifier was able to predict the intended target character at or near 100% accuracy using fewer than 15 stimulation sequences in 5 of the 6 people tested. ECOG data from electrodes outside the language cortex contributed to the classifier and enabled participants to write words on a visual keyboard. This is a novel finding because previous invasive BCI research in humans used signals exclusively from the motor cortex to control a computer cursor or prosthetic device. These results demonstrate that ECOG signals from electrodes both overlying and outside the language cortex can reliably control a visual keyboard to generate language output without voice or limb movements.

  8. 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.

  9. Effects of Motion in the Far Peripheral Visual Field on Cognitive Test Performance and Cognitive Load.

    Science.gov (United States)

    Bevilacqua, Andy; Paas, Fred; Krigbaum, Genomary

    2016-04-01

    Cognitive load theory posits that limited attention is in actuality a limitation in working memory resources. The load theory of selective attention and cognitive control sees the interplay between attention and awareness as separate modifying functions that act on working memory. Reconciling the theoretical differences in these two theories has important implications for learning. Thirty-nine adult participants performed a cognitively demanding test, with and without movement in the far peripheral field. Although the results for movement effects on cognitive load in this experiment were not statistically significant, men spent less time on the cognitive test in the peripheral movement condition than in the conditions without peripheral movement. No such difference was found for women. The implications of these results and recommendations for future research that extends the present study are presented. © The Author(s) 2016.

  10. The Effects of Social Anxiety and State Anxiety on Visual Attention: Testing the Vigilance-Avoidance Hypothesis.

    Science.gov (United States)

    Singh, J Suzanne; Capozzoli, Michelle C; Dodd, Michael D; Hope, Debra A

    2015-01-01

    A growing theoretical and research literature suggests that trait and state social anxiety can predict attentional patterns in the presence of emotional stimuli. The current study adds to this literature by examining the effects of state anxiety on visual attention and testing the vigilance-avoidance hypothesis, using a method of continuous visual attentional assessment. Participants were 91 undergraduate college students with high or low trait fear of negative evaluation (FNE), a core aspect of social anxiety, who were randomly assigned to either a high or low state anxiety condition. Participants engaged in a free view task in which pairs of emotional facial stimuli were presented and eye movements were continuously monitored. Overall, participants with high FNE avoided angry stimuli and participants with high state anxiety attended to positive stimuli. Participants with high state anxiety and high FNE were avoidant of angry faces, whereas participants with low state and low FNE exhibited a bias toward angry faces. The study provided partial support for the vigilance-avoidance hypothesis. The findings add to the mixed results in the literature that suggest that both positive and negative emotional stimuli may be important in understanding the complex attention patterns associated with social anxiety. Clinical implications and suggestions for future research are discussed.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

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

    Science.gov (United States)

    2015-12-01

    course  of  the  project,  we  integrated  novel  product-­‐ready  hardware  solutions  to  implement  several   test...database  (e.g.,   MySQL )  at  this  stage  for  data  warehousing  purposes.  A  well-­‐designed  database   will  support...significant  number  of  subpar  quality  or  "bad"  data   points  during  the   course

  20. 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.

  1. 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.

  2. Use of digital impression systems with intraoral scanners for fabricating restorations and fixed dental prostheses.

    Science.gov (United States)

    Takeuchi, Yoshimasa; Koizumi, Hiroyasu; Furuchi, Mika; Sato, Yohei; Ohkubo, Chikahiro; Matsumura, Hideo

    2018-01-01

    Accurate impressions are essential in fabri-cating dental restorations and fixed dental prostheses. During the last decade, digital impression systems have improved substantially. This review discusses the accuracy of digital impression systems for fabrication of dental restorations and fixed dental prostheses. A literature search in PubMed was performed for the period from July 2010 through June 2017. The search keywords were Cerec, digital impression, direct digitalization, indirect digitalization, and intraoral scanner. Only relevant studies are summarized and discussed in this review. In general, the latest systems have considerably reduced the time required for impression making, and the accuracy and marginal fit of digital impression systems have recently improved. Restorations and fixed dental prostheses fabricated with currently available digital impression systems and intraoral scanners exhibit clinically acceptable ranges of marginal gap in both direct and indirect procedures.

  3. 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

  4. Visual Memories Bypass Normalization.

    Science.gov (United States)

    Bloem, Ilona M; Watanabe, Yurika L; Kibbe, Melissa M; Ling, Sam

    2018-05-01

    How distinct are visual memory representations from visual perception? Although evidence suggests that briefly remembered stimuli are represented within early visual cortices, the degree to which these memory traces resemble true visual representations remains something of a mystery. Here, we tested whether both visual memory and perception succumb to a seemingly ubiquitous neural computation: normalization. Observers were asked to remember the contrast of visual stimuli, which were pitted against each other to promote normalization either in perception or in visual memory. Our results revealed robust normalization between visual representations in perception, yet no signature of normalization occurring between working memory stores-neither between representations in memory nor between memory representations and visual inputs. These results provide unique insight into the nature of visual memory representations, illustrating that visual memory representations follow a different set of computational rules, bypassing normalization, a canonical visual computation.

  5. 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

  6. What are estimated reimbursements for lower extremity prostheses capable of surgical and nonsurgical lengthening?

    Science.gov (United States)

    Henderson, Eric R; Pepper, Andrew M; Letson, G Douglas

    2012-04-01

    Growing prostheses accommodate skeletally immature patients with bone tumors undergoing limb-preserving surgery. Early devices required surgical procedures for lengthening; recent devices lengthen without surgery. Expenses for newer expandable devices that lengthen without surgery are more than for their predecessors but overall reimbursement amounts are not known. We sought to determine reimbursement amounts associated with lengthening of growing prostheses requiring surgical and nonsurgical lengthening. We retrospectively reviewed 17 patients with growing prostheses requiring surgical expansion and eight patients with prostheses capable of nonsurgical expansion. Insurance documents were reviewed to determine the reimbursement for implantation, lengthening, and complications. Growth data were obtained from the literature. Mean reimbursement amounts of surgical and nonsurgical lengthenings were $9950 and $272, respectively. Estimated reimbursements associated with implantation of a growing prosthesis varied depending on age, sex, and location. The largest difference was found for 4-year-old boys with distal femoral replacement where reimbursement for expansion to maturity for surgical and nonsurgical lengthening prostheses would be $379,000 and $208,000, respectively. For children requiring more than one surgical expansion, net reimbursements were lower when a noninvasive lengthening device was used. Annual per-prosthesis maintenance reimbursements to address complications for surgical and nonsurgical lengthening prostheses were $3386 and $1856, respectively. This study showed that reimbursements for lengthening of growing endoprostheses capable of nonsurgical expansion may be less expensive in younger patients, particularly male patients undergoing distal femur replacement, than endoprostheses requiring surgical lengthening. Longer outcomes studies are required to see if reimbursements for complications differ between devices. Level III, economic and decision

  7. 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.

  8. 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

  9. 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.

  10. Effect of tightening torque on the marginal adaptation of cement-retained implant-supported fixed dental prostheses.

    Science.gov (United States)

    Ghanbarzadeh, Jalil; Dashti, Hossin; Karamad, Reza; Alikhasi, Marzieh; Nakhaei, Mohammadreza

    2015-01-01

    The final position of the abutment changes with the amount of tightening torque. This could eventually lead to loss of passivity and marginal misfit of prostheses. The aim of this study was to evaluate the effect of three different tightening torques on the marginal adaptation of 3-unit cement-retained implant-supported fixed dental prostheses (FDPs). Two implants (Straumann) were inserted in an acrylic block so that one of the implants was placed vertically and the other at a 15° vertical angle. A straight abutment and a 15° angulated abutment were connected to the vertically and obliquely installed implants, respectively, so that the two abutments were parallel. Then, 10 cement-retained FDPs were waxed and cast. Abutments were tightened with 10, 20, and 35 Ncm torques, respectively. Following each tightening torque, FDPs were luted on respective abutments with temporary cement. The marginal adaptation of the retainers was evaluated using stereomicroscope. FDPs were then removed from the abutments and were sectioned at the connector sites. The retainers were luted again on their respective abutments. Luting procedures and marginal adaptation measurement were repeated. Data were analyzed by ANOVA and least significant difference tests (α = 0.05). After cutting the FDP connectors, the independent samples t-test was used to compare misfit values (α = 0.05). Following 10, 20, and 35 Ncm tightening torques, the marginal discrepancy of the retainers of FDPs significantly increased (P marginal discrepancies of these two retainers (P > 0.05). The marginal gap values of angulated abutment retainers (ANRs) were significantly higher than those of the straight abutment after cutting the connectors (P = 0.026). Within the limitations of this study, the marginal misfit of cement-retained FDPs increased continuously when the tightening torque increased. After cutting the connectors, the marginal misfit of the ANRs was higher than those of the straight abutment retainers.

  11. Prostheses and orthoses in the collections of the Auschwitz-Birkenau State Museum.

    Science.gov (United States)

    Przeździak, Bogumił; Lutomirski, Adam; Kulczyk, Maria

    2011-01-01

    The authors described 424 orthopaedic appliances left by the prisoners of the Nazi Concentration Camp in Oświęcim. A collection of prostheses and orthoses, which is currently a part of the Auschwitz-Birkenau State Museum's exhibition, is extraordinary as it illustrates the fate of innocent, crippled people, who were incarcerated and murdered. Another point of value of the collection is its technical aspect, as it provides a clear picture of construction of prostheses and orthoses at the beginning of the 20th century.

  12. External breast prostheses. A survey of their use by women after mastectomy.

    Science.gov (United States)

    Tanner, R; Abraham, S F; Llewellyn-Jones, D

    1983-03-19

    Women who have had a mastectomy for breast cancer have to cope with two major problems: first, that they have cancer, and second, that they have lost their physical appearance. The provision of an appropriate prosthesis can reduce the sense of disfigurement. If women were to obtain the full psychological benefit of wearing a breast prosthesis, they need to be informed about the available breast forms, have an opportunity to choose between them, and to be satisfied with their choice. In this study of 49 women, only 44% had had the opportunity to choose a prosthesis, 28% were dissatisfied with their prostheses, and 17% were still using temporary prostheses.

  13. 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

  14. 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 important factor for students in acquiring a successful understanding of quantum mechanics.

  15. 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.

  16. The pointillism method for creating stimuli suitable for use in computer-based visual contrast sensitivity testing.

    Science.gov (United States)

    Turner, Travis H

    2005-03-30

    An increasingly large corpus of clinical and experimental neuropsychological research has demonstrated the utility of measuring visual contrast sensitivity. Unfortunately, existing means of measuring contrast sensitivity can be prohibitively expensive, difficult to standardize, or lack reliability. Additionally, most existing tests do not allow full control over important characteristics, such as off-angle rotations, waveform, contrast, and spatial frequency. Ideally, researchers could manipulate characteristics and display stimuli in a computerized task designed to meet experimental needs. Thus far, 256-bit color limitation in standard cathode ray tube (CRT) monitors has been preclusive. To this end, the pointillism method (PM) was developed. Using MATLAB software, stimuli are created based on both mathematical and stochastic components, such that differences in regional luminance values of the gradient field closely approximate the desired contrast. This paper describes the method and examines its performance in sine and square-wave image sets from a range of contrast values. Results suggest the utility of the method for most experimental applications. Weaknesses in the current version, the need for validation and reliability studies, and considerations regarding applications are discussed. Syntax for the program is provided in an appendix, and a version of the program independent of MATLAB is available from the author.

  17. Facial expressions as a model to test the role of the sensorimotor system in the visual perception of the actions.

    Science.gov (United States)

    Mele, Sonia; Ghirardi, Valentina; Craighero, Laila

    2017-12-01

    A long-term debate concerns whether the sensorimotor coding carried out during transitive actions observation reflects the low-level movement implementation details or the movement goals. On the contrary, phonemes and emotional facial expressions are intransitive actions that do not fall into this debate. The investigation of phonemes discrimination has proven to be a good model to demonstrate that the sensorimotor system plays a role in understanding actions acoustically presented. In the present study, we adapted the experimental paradigms already used in phonemes discrimination during face posture manipulation, to the discrimination of emotional facial expressions. We submitted participants to a lower or to an upper face posture manipulation during the execution of a four alternative labelling task of pictures randomly taken from four morphed continua between two emotional facial expressions. The results showed that the implementation of low-level movement details influence the discrimination of ambiguous facial expressions differing for a specific involvement of those movement details. These findings indicate that facial expressions discrimination is a good model to test the role of the sensorimotor system in the perception of actions visually presented.

  18. 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

  19. [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 indextechnical 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 not yield

  20. [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

  1. [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

  2. 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

  3. Restoring natural sensory feedback in real-time bidirectional hand prostheses

    DEFF Research Database (Denmark)

    Raspopovic, Stanisa; Capogrosso, Marco; Petrini, Francesco Maria

    2014-01-01

    Hand loss is a highly disabling event that markedly affects the quality of life. To achieve a close to natural replacement for the lost hand, the user should be provided with the rich sensations that we naturally perceive when grasping or manipulating an object. Ideal bidirectional hand prosthese...

  4. 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

  5. [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

  6. The development of artificial organs and prostheses worldwide and in the Ottoman Empire.

    Science.gov (United States)

    Birdane, Leman; Cingi, Cemal; Elçioğlu, Ömür; Muluk, Nuray Bayar

    2016-08-01

    An artificial organ or prosthesis is a man-made device that is implanted or integrated into a human to replace a natural organ. There were many historical steps in the development of artificial organs and prostheses. New surgical techniques, the development of prosthetic materials and the creative ideas of engineers led to progress in this field. © The European Society of Cardiology 2014.

  7. 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

  8. [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

  9. 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.

  10. PATENCY AND HEALING OF MICROVASCULAR PROSTHESES - A REVIEW OF 10 YEARS OF EXPERIMENTAL WORK IN GRONINGEN

    NARCIS (Netherlands)

    VANDERLEI, B; ROBINSON, PH

    1993-01-01

    From 1982 onwards, in Groningen, The Netherlands, we have worked on the experimental evaluation and development of microvascular prostheses in rats and rabbits. In this review article a systematic overview of this experimental work is presented and the results are discussed with regard to the

  11. Screening of patients for first time prostheses after amputation of lower limbs

    Directory of Open Access Journals (Sweden)

    Vetra A.

    2016-01-01

    More than 25% of those who followed the recommended treatment and rehabilitation programme to prepare the amputation stump, reduced contracture and enhanced physical working abilities were declared to be appropriate for further prostheses. This indicates serious shortcomings in medical treatments during the early post-amputation period.

  12. 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…

  13. 1/12-Scale mixing interface visualization and buoyant particle release tests in support of Tank 241-SY-101 hydrogen mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Eschbach, E.J.; Enderlin, C.W.

    1993-10-01

    In support of tank waste safety programs, visualization tests were performed in the 1/12-scale tank facility, using a low-viscosity simulant. The primary objective of the tests was to obtain video records of the transient jet-sludge interaction. The intent is that these videos will provide useful qualitative data for comparison with model predictions. Two tests were initially planned: mixing interface visualization (MIV) and buoyant particle release (BPR). Completion of the buoyant particle release test was set aside in order to complete additional MIV tests. Rheological measurements were made on simulant samples before testing, and the simulant was found to exhibit thixotropic behavior. Shear vane measurements were also made on an in-situ analog of the 1/12-scale tank simulant. Simulant shear strength has been observed to be time dependent. The primary objective of obtaining video records of jet-sludge interaction was satisfied, and the records yielded jet location information which may be of use in completing model comparisons. The modeling effort is not part of this task, but this report also discusses test specific instrumentation, visualization techniques, and shear vane instrumentation which would enable improved characterization of jet-sludge interaction and simulant characteristics.

  14. 1/12-Scale mixing interface visualization and buoyant particle release tests in support of Tank 241-SY-101 hydrogen mitigation

    International Nuclear Information System (INIS)

    Eschbach, E.J.; Enderlin, C.W.

    1993-10-01

    In support of tank waste safety programs, visualization tests were performed in the 1/12-scale tank facility, using a low-viscosity simulant. The primary objective of the tests was to obtain video records of the transient jet-sludge interaction. The intent is that these videos will provide useful qualitative data for comparison with model predictions. Two tests were initially planned: mixing interface visualization (MIV) and buoyant particle release (BPR). Completion of the buoyant particle release test was set aside in order to complete additional MIV tests. Rheological measurements were made on simulant samples before testing, and the simulant was found to exhibit thixotropic behavior. Shear vane measurements were also made on an in-situ analog of the 1/12-scale tank simulant. Simulant shear strength has been observed to be time dependent. The primary objective of obtaining video records of jet-sludge interaction was satisfied, and the records yielded jet location information which may be of use in completing model comparisons. The modeling effort is not part of this task, but this report also discusses test specific instrumentation, visualization techniques, and shear vane instrumentation which would enable improved characterization of jet-sludge interaction and simulant characteristics

  15. 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 sativum 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.

  16. Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm

    Directory of Open Access Journals (Sweden)

    Sanrrangers Sales Silva

    Full Text Available ABSTRACT Aspiration of oral bacteria leads to cardiac and respiratory infectious diseases and dentures can act as a reservoir for pathogenic microorganisms. Objective: To determine the occurrence and the in vitro antimicrobial susceptibility of enteric rods and pseudomonads from the denture biofilm of 52 subjects at the Center for Dental Specialties of Sobral/ Ceara, Brazil. Material and Methods: Denture biofilm was collected and samples plated on MacConkey agar. The isolated bacterial colonies were identified using the BBL Crystal enteric/non-fermenter system. Antibiotic bacterial susceptibility was assessed by the disc diffusion method of amoxicillin, amoxicillin/clavulanic acid, doxycycline, tetracycline, tobramycin, imipenem, cefotaxime, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC of cefotaxime, tobramycin, doxycycline, imipenem, and ciprofloxacin was determined for 40 species by E-test. Results: 34 subjects (65.4% harbored enteric rods in their prostheses. Klebsiella pneumoniae (26.5%, Escherichia coli (23.5%, and Enterobacter aerogenes (23.5% were the most prevalent species. All organisms were susceptible to ciprofloxacin and most species were resistant to amoxicillin or amoxicillin/clavulanic acid, demonstrating variable sensitivity patterns to other antimicrobials. However, the MIC showed the emergence of strains with reduced sensitivity to ciprofloxacin (MIC90≥3 μg/ mL and cefotaxime (MIC90≥2 μg/mL. Conclusion: The findings show high prevalence of nosocomial diseases-related bacterial species and low susceptibility to antimicrobial drugs. Therefore, these results imply caution against the indiscriminate use of broad spectrum antibiotics in dental practice.

  17. Temperature variations in sintering ovens for metal ceramic dental prostheses: non-destructive assessment using OCT

    Science.gov (United States)

    Sinescu, C.; Bradu, A.; Duma, V.-F.; Topala, F. I.; Negrutiu, M. L.; Podoleanu, A. G.

    2018-02-01

    We present a recent investigation regarding the use of optical coherence tomography (OCT) in the monitoring of the calibration loss of sintering ovens for the manufacturing of metal ceramic dental prostheses. Differences in the temperatures of such ovens with regard to their specifications lead to stress and even cracks in the prostheses material, therefore to the failure of the dental treatment. Evaluation methods of the ovens calibration consist nowadays of firing supplemental samples; this is subjective, expensive, and time consuming. Using an in-house developed swept source (SS) OCT system, we have demonstrated that a quantitative assessment of the internal structure of the prostheses, therefore of the temperature settings of the ovens can be made. Using en-face OCT images acquired at similar depths inside the samples, the differences in reflectivity allow for the evaluation of the differences in granulation (i.e., in number and size of ceramic grains) of the prostheses material. Fifty samples, divided in five groups, each sintered at different temperatures (lower, higher, or equal to the prescribed one) have been analyzed. The consequences of the temperature variations with regard to the one prescribed were determined. Rules-of-thumb were extracted to monitor objectively, using only OCT images of currently manufactured samples, the settings of the oven. The method proposed allows for avoiding producing prostheses with defects. While such rules-of-thumb achieve a qualitative assessment, an insight in our on-going work on the quantitative assessment of such losses of calibration on dental ovens using OCT is also made.

  18. 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.

  19. 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

  20. Oral health-related quality of life of implant-supported overdentures versus conventional complete prostheses: Retrospective study of a cohort of edentulous patients.

    Science.gov (United States)

    Fernandez-Estevan, Lucia; Selva-Otaolaurruchi, Eduardo J; Montero, Javier; Sola-Ruiz, Fernanda

    2015-07-01

    This work aims to confirm if implant-supported overdentures are a good treatment option for edentulous patients and offer an improvement in quality of life compared with traditional complete prostheses (dentures). This retrospective clinical descriptive study included three evaluation groups: validation group (n=57); control group of patients with complete removeable prostheses (n=56); study group of patients with implant-supported overdentures retained with the Locator® system (n=80). The study also validated the Oral Health Impact Profile-20 questionnaire. Individual protocols were created that included socio-demographic data, the Oral Health Impact Profile-20 (OHIP-20) questionnaire and Oral Satisfaction Scale (OSS). Descriptive and bivariate statistical analysis was carried out applying χ², Pearson, Kruskal-Wallis, and Student t tests, transferring data into SPSS-Windows® software from a Microsoft® Excel spreadsheet. The OHIP-20 proved to be a valid instrument and provided reliable assessment of health-related quality of life among both the Spanish general population and edentulous patients. The control and study groups proved comparable, showing socio-demographic homogeneity. For patients with overdentures retained by means of the Locator® system, these restorations had significantly lower impact on quality of life (19 vs 33), both generally and for each individual questionnaire item, and much higher satisfaction with the state of their oral cavities (8.3 vs 5.3) than patients wearing dentures; both sets of data showed a direct linear relationship, so that as the level of impact on quality of life increased, perceived oral satisfaction worsened. Patients rehabilitated with implant supported overdentures retained by the Locator® system, presented significantly lower levels of impact on their quality of life and significantly higher oral satisfaction than patients with conventional complete prostheses.

  1. 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.

  2. 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.

  3. Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive

    Science.gov (United States)

    Spreng, Lucie; Favrat, Bernard; Borruat, François-Xavier; Vaucher, Paul

    2018-01-01

    Objectives The aim of this study is to quantify the importance of loss of contrast sensitivity (CS) and its relationship to loss of visual acuity (VA), driving restrictions and daytime, on-road driving evaluations in drivers aged 70+. Design A predictive cross-sectional study. Setting Volunteer participants to a drivers’ refresher course for adults aged 70+ delivered by the Swiss Automobile Club in western Switzerland from 2011 to 2013. Participants 162 drivers, male and female, aged 70 years or older. Clinical predictors We used a vision screener to estimate VA and the The Mars Letter Contrast Sensitivity Test to test CS. Outcomes We asked drivers to report whether they found five driving restrictions useful for their condition; restrict driving to known roads, avoid driving on highways, avoid driving in the dark, avoid driving in dense traffic and avoid driving in fog. All participants also underwent a standardised on-road evaluation carried out by a driving instructor. Results Moderate to severe loss of CS for at least one eye was frequent (21.0% (95% CI 15.0% to 28.1%)) and often isolated from a loss of VA (11/162 cases had a VA ≥0.8 decimal and a CS of ≤1.5 log(CS); 6.8% (95% CI 3.4% to 11.8%)). Drivers were more likely (R2=0.116, P=0.004) to report a belief that self-imposed driving restrictions would be useful if they had reduced CS in at least one eye. Daytime evaluation of driving performance seems limited in its ability to correctly identify difficulties related to CS loss (VA: R2=0.004, P=0.454; CS: R2=0.006, P=0.332). Conclusion CS loss is common for older drivers. Screening CS and referring for cataract surgery even in the absence of VA loss could help maintain mobility. Reduced CS and moderate reduction of VA were both poor predictors of daytime on-road driving performances in this research study. PMID:29374663

  4. The BEVPS: A new test battery to assess visual perceptual and spatial processing abilities in 5-14 year-old children.

    Science.gov (United States)

    Schmetz, Emilie; Rousselle, Laurence; Ballaz, Cécile; Detraux, Jean-Jacques; Barisnikov, Koviljka

    2017-06-20

    This study aims to examine the different levels of visual perceptual object recognition (early, intermediate, and late) defined in Humphreys and Riddoch's model as well as basic visual spatial processing in children using a new test battery (BEVPS). It focuses on the age sensitivity, internal coherence, theoretical validity, and convergent validity of this battery. French-speaking, typically developing children (n = 179; 5 to 14 years) were assessed using 15 new computerized subtests. After selecting the most age-sensitive tasks though ceiling effect and correlation analyses, an exploratory factorial analysis was run with the 12 remaining subtests to examine the BEVPS' theoretical validity. Three separate factors were identified for the assessment of the stimuli's basic features (F1, four subtests), view-dependent and -independent object representations (F2, six subtests), and basic visual spatial processing (F3, two subtests). Convergent validity analyses revealed positive correlations between F1 and F2 and the Beery-VMI visual perception subtest, while no such correlations were found for F3. Children's performances progressed until the age of 9-10 years in F1 and in view-independent representations (F2), and until 11-12 years in view-dependent representations (F2). However, no progression with age was observed in F3. Moreover, the selected subtests, present good-to-excellent internal consistency, which indicates that they provide reliable measures for the assessment of visual perceptual processing abilities in children.

  5. 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.

  6. Impact of implant-supported prostheses on nutritional status and oral health perception in edentulous patients.

    Science.gov (United States)

    El Osta, Nada; El Osta, Lana; Moukaddem, Farah; Papazian, Tatiana; Saad, Robert; Hennequin, Martine; Rabbaa Khabbaz, Lydia

    2017-04-01

    Improvement of nutritional status and perception of oral health are supposed to be different with complete conventional denture or implant-supported fixed or removable prostheses. Since no study has been conducted in Lebanon, the aim of our study was to assess the nutritional status and oral heath related quality of life (OHRQoL) in totally edentulous patients after treatment with complete denture or implant supported-prostheses. This was an observational clinical prospective study. A convenient sample of Lebanese people aged 60 years or more was selected between September 2013 and July 2015 from the Departments of removable and fixed prosthesis at Saint-Joseph University of Beirut. The treatment options included complete denture, implant-supported complete denture and implant-supported fixed prostheses. Nutritional status and OHRQoL were assessed with the Mini-Nutritional Assessment Index (MNA) and the Geriatric Oral Health Assessment Index (GOHAI) respectively at Baseline (first visit before treatment), 2-3 weeks after treatment (t1), 3 months (t2) and 6 months (t3) after treatment. Fifty-one participants (mean age: 69.39 ± 7.164 years) were included. The results have shown an improvement over time in nutritional status and OHRQoL for all treatment groups. However, 2-3 weeks after treatment the number of participants at risk of malnutrition was higher with complete removable denture, intermediate with implant-supported complete denture and lower with implant-supported fixed prostheses (p-value = 0.049). Moreover, the mean GOHAI score was significantly lower over time with complete removable denture compared to implant-supported prostheses (p-value nutritional status for implant supported-prostheses compared to conventional removable dentures. Therefore, it is fundamental that dentists communicate with their patients about implant treatment to understand their expectations, to explain the outcomes and achieve the desired clinical result. Copyright © 2017

  7. 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

  8. 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.

  9. 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, Psafely.

  10. Effect of treatment with fixed and removable dental prostheses. An oral health-related quality of life study

    DEFF Research Database (Denmark)

    Øzhayat, Esben Boeskov; Gotfredsen, Klaus

    2012-01-01

    The aim of the study was to evaluate patient-reported effects of treatment with fixed dental prostheses (FDP) and removable dental prostheses (RDP) and relate the change in Oral Health Related Quality of Life (OHRQoL) to the type of treatment and objective dental variables of aesthetics and masti......The aim of the study was to evaluate patient-reported effects of treatment with fixed dental prostheses (FDP) and removable dental prostheses (RDP) and relate the change in Oral Health Related Quality of Life (OHRQoL) to the type of treatment and objective dental variables of aesthetics...... were obtained. The participants completed the Oral Health Impact Profile 49 (OHIP-49) before and after treatment. A control group with no need for dental treatment also completed the OHIP-49. All participants had a significant improvement in OHRQoL. The improvement was higher for the RDP group than...

  11. 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),

  12. 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.

  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. 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

  15. 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 . These children were found to be less proficient in visualisation skills than their suburban counterparts. A new study was undertaken to ascertain whether there is any difference in cognitive skills, particularly visual perception, between pre-school children from...

  16. [Endo-exo prostheses : Osseointegrated percutaneously channeled implants for rehabilitation after limb amputation].

    Science.gov (United States)

    Aschoff, H-H; Juhnke, D-L

    2016-05-01

    In 1999 the first endo-exo femoral prosthesis (EEFP) was implanted in Germany in a patient who had suffered a traumatic above-knee amputation. This procedure involves a skeletally anchored exoprosthetic device that is inserted into the residual femur. The distal part of the implant protrudes transcutaneously and allows attachment to a prosthetic limb which provides direct force transmission to the external prosthetic components. The technique originated from dental implantology and helps to avoid possible problems resulting from treatment of amputated limbs using socket prostheses. In the meantime, durability times of over 10 years have now helped to invalidate the initially well-founded reservations held against the procedure. What advantages can be achieved by osseointegrated and percutaneously channeled prostheses and which problems had to be overcome for treatment. Critical evaluation of data from patients operated on in Lübeck, Germany from January 2003 to December 2014. With osseointegrated and percutaneously channeled prostheses permanent durability times can be achieved. Infection-associated soft tissue problems at the site of skin protrusion (stoma) can be successfully prevented. The creation of this so-called stoma means acceptance of a possible bacterial portal of entry into the body. Patient satisfaction has so far been high, postoperative rehabilitation is simplified and the technique could possibly lower the costs of medical treatment. Endo-exo prostheses have proved to be successful for more than 15 years. A critical appraisal of the indications as well as a close cooperation between the surgeon, orthopedic technician and the associated rehabilitation facilities with the patient are the basis for the long-term success of this relatively new treatment approach.

  17. A fractographic study of clinically retrieved zirconia–ceramic and metal–ceramic fixed dental prostheses

    OpenAIRE

    Pang, Zhen; Chughtai, Asima; Sailer, Irena; Zhang, Yu

    2015-01-01

    A recent 3-year randomized controlled trial (RCT) of tooth supported three- to five-unit zirconia-ceramic and metal-ceramic posterior fixed dental prostheses (FDPs) revealed that veneer chipping and fracture in zirconia-ceramic systems occurred more frequently than those in metal-ceramic systems [1]. This study seeks to elucidate the underlying mechanisms responsible for the fracture phenomena observed in this RCT using a descriptive fractographic analysis

  18. Integration of the Residual Limb with Prostheses via Direct Skin-Bone-Peripheral Nerve Interface

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-16-1-0791 TITLE: Integration of the Residual Limb with Prostheses via Direct Skin- Bone-Peripheral Nerve Interface...ABOVE ADDRESS. 1. REPORT DATE October 2017 2. REPORT TYPE Annual 3. DATES COVERED 30 Sep 2016 - 29 Sep 2017 4. TITLE AND SUBTITLE Integration of the...translational study to develop Skin and Bone Integrated Pylon with Peripheral Neural Interface (SBIP-PNI) directly attached to the residuum and the

  19. Ranking of CT in persistent vertigo after implantation of stapes prostheses

    International Nuclear Information System (INIS)

    Koesling, S.; Woldag, K.; Meister, E.F.; Reschke, I.; Schulz, H.G.

    1995-01-01

    10 of 150 patients had persistent vertigo after implanation of stapes prostheses. These patients were evaluated by high resolution CT in the axial and coronal plane. Scans showed in all cases findings which related to the symptoms. The CT findings were proved intraoperatively in 9 cases. A new indirect sign of a perilymphatic fistula is described in form of an air bulla at the end of the prosthesis. Retympanotomy could be planned better with the help of HR-CT. (orig.) [de

  20. 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

  1. Application of quality by design for 3D printed bone prostheses and scaffolds.

    Science.gov (United States)

    Martinez-Marquez, Daniel; Mirnajafizadeh, Ali; Carty, Christopher P; Stewart, Rodney A

    2018-01-01

    3D printing is an emergent manufacturing technology recently being applied in the medical field for the development of custom bone prostheses and scaffolds. However, successful industry transformation to this new design and manufacturing approach requires technology integration, concurrent multi-disciplinary collaboration, and a robust quality management framework. This latter change enabler is the focus of this study. While a number of comprehensive quality frameworks have been developed in recent decades to ensure that the manufacturing of medical devices produces reliable products, they are centred on the traditional context of standardised manufacturing techniques. The advent of 3D printing technologies and the prospects for mass customisation provides significant market opportunities, but also presents a serious challenge to regulatory bodies tasked with managing and assuring product quality and safety. Before 3D printing bone prostheses and scaffolds can gain traction, industry stakeholders, such as regulators, clients, medical practitioners, insurers, lawyers, and manufacturers, would all require a high degree of confidence that customised manufacturing can achieve the same quality outcomes as standardised manufacturing. A Quality by Design (QbD) approach to custom 3D printed prostheses can help to ensure that products are designed and manufactured correctly from the beginning without errors. This paper reports on the adaptation of the QbD approach for the development process of 3D printed custom bone prosthesis and scaffolds. This was achieved through the identification of the Critical Quality Attributes of such products, and an extensive review of different design and fabrication methods for 3D printed bone prostheses. Research outcomes include the development of a comprehensive design and fabrication process flow diagram, and categorised risks associated with the design and fabrication processes of such products. An extensive systematic literature review

  2. 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.)

  3. Application of quality by design for 3D printed bone prostheses and scaffolds

    Science.gov (United States)

    Martinez-Marquez, Daniel; Mirnajafizadeh, Ali; Carty, Christopher P.

    2018-01-01

    3D printing is an emergent manufacturing technology recently being applied in the medical field for the development of custom bone prostheses and scaffolds. However, successful industry transformation to this new design and manufacturing approach requires technology integration, concurrent multi-disciplinary collaboration, and a robust quality management framework. This latter change enabler is the focus of this study. While a number of comprehensive quality frameworks have been developed in recent decades to ensure that the manufacturing of medical devices produces reliable products, they are centred on the traditional context of standardised manufacturing techniques. The advent of 3D printing technologies and the prospects for mass customisation provides significant market opportunities, but also presents a serious challenge to regulatory bodies tasked with managing and assuring product quality and safety. Before 3D printing bone prostheses and scaffolds can gain traction, industry stakeholders, such as regulators, clients, medical practitioners, insurers, lawyers, and manufacturers, would all require a high degree of confidence that customised manufacturing can achieve the same quality outcomes as standardised manufacturing. A Quality by Design (QbD) approach to custom 3D printed prostheses can help to ensure that products are designed and manufactured correctly from the beginning without errors. This paper reports on the adaptation of the QbD approach for the development process of 3D printed custom bone prosthesis and scaffolds. This was achieved through the identification of the Critical Quality Attributes of such products, and an extensive review of different design and fabrication methods for 3D printed bone prostheses. Research outcomes include the development of a comprehensive design and fabrication process flow diagram, and categorised risks associated with the design and fabrication processes of such products. An extensive systematic literature review

  4. Comparison of fixed implant-supported prostheses, removable implant-supported prostheses, and complete dentures: patient satisfaction and oral health-related quality of life.

    Science.gov (United States)

    Oh, Sung-Hee; Kim, Younhee; Park, Joo-Yeon; Jung, Yea Ji; Kim, Seong-Kyun; Park, Sun-Young

    2016-02-01

    The purpose of this study was to compare patient satisfaction and oral health-related quality of life (OHRQoL) among fully edentulous patients treated with either fixed implant-supported prostheses (FP), removable implant-supported prostheses (RP), or complete dentures (CD). Eighty-six patients - 29 FP, 27 RP, and 30 CD patients - participated in this study. The survey was conducted using face-to-face interviews with a questionnaire that included a patient satisfaction scale and Oral Health Impact Profile (OHIP-14). We measured patient satisfaction after prosthetic treatments and OHRQoL before and after the treatments. After prosthetic treatments, OHRQoL increased in all three groups (P patient satisfaction and OHRQoL, and both groups showed greater improvement compared with the CD group. Specifically, the OHRQoL dimensions of functional limitation, physical pain, psychological discomfort, and psychological disability in the FP group, and functional limitation in the RP group, improved greatly in comparison with the CD group (P patient satisfaction than the CD treatment. Reliable information of OHRQoL and patient satisfaction helps experts and patients choose the best prosthetic treatment option. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Crossover study of amputee stair ascent and descent biomechanics using Genium and C-Leg prostheses with comparison to non-amputee control.

    Science.gov (United States)

    Lura, Derek J; Wernke, Matthew W; Carey, Stephanie L; Kahle, Jason T; Miro, Rebecca M; Highsmith, M Jason

    2017-10-01

    This study was a randomized crossover of stair ambulation of Transfemoral Amputees (TFAs) using the Genium and C-Leg prosthetic knees. TFAs typically have difficulty ascending and descending stairs, limiting community mobility. The objective of this study was to determine the relative efficacy of the Genium and C-Leg prostheses for stair ascent and descent, and their absolute efficacy relative to non-amputees. Twenty TFAs, and five non-amputees participated in the study. TFAs were randomized to begin the study with the Genium or C-Leg prosthesis. Informed consent was obtained from all participants prior to data collection and the study was listed on clinicaltrials.gov (#NCT01473662). After fitting, accommodation, and training, participants were asked to demonstrate their preferred gait pattern for stair ascent and descent and a step-over-step pattern if able. TFAs then switched prosthetic legs and repeated fitting, accommodation, training, and testing. An eight camera Vicon optical motion analysis system, and two AMTI force plates were used to track and analyze the participants' gait patterns, knee flexion angles, knee moment normalized by body weight, and swing time. For stair descent, no significant differences were found between prostheses. For stair ascent, Genium use resulted in: increased ability to use a step-over-step gait pattern (p=0.03), increased prosthetic side peak knee flexion (pstair ascent relative to the C-Leg, by enabling gait patterns that more closely resembled non-amputees. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Influence of varus/valgus positioning of the Nanos® and Metha® short-stemmed prostheses on stress shielding of metaphyseal bone.

    Science.gov (United States)

    Brinkmann, V; Radetzki, F; Gutteck, N; Delank, S; Zeh, A

    2017-03-01

    The aim of this study was to analyze bone remodeling around the Nanos® (Smith & Nephew) and Metha® (Aesculap AG) implants as a function of varus/valgus stem positioning. In 75 patients with diagnosed coxarthrosis, either Nanos® (n= 51) or Metha® (n= 24) prostheses were implanted. Digital assessment of plain radiographs immediately, 97 days, and 381 days after THA showed no clinically-relevant migration, angulation, or change in offset and center of rotation. The DEXA scans showed significant BMD changes in Gruen zones 1 (-12.8%), 2 (-3.3%), 6 (+6.4%), and 7(-7.8%)(t-test). The pre/postoperative CCD for the Nanos® was 129°/ 135° and for the Metha® 131°/ 127°. Linear regression analysis showed no prediction for BMD by postoperative CCD or stem type. In conclusion, there was no clinically-relevant influence on proximal femur BMD according to varus/valgus implantation of the Nanos® or Metha® prostheses.

  7. Cyclic stress-strain behavior of polymeric nonwoven structures for the use as artificial leaflet material for transcatheter heart valve prostheses

    Directory of Open Access Journals (Sweden)

    Arbeiter Daniela

    2017-09-01

    Full Text Available Xenogenic leaflet material, bovine and porcine pericardium, is widely used for the fabrication of surgically implanted and transcatheter heart valve prostheses. As a biological material, long term durability of pericardium is limited due to calcification, degeneration and homogeneity. Therefore, polymeric materials represent a promising approach for a next generation of artificial heart valve leaflets with improved durability. Within the current study we analyzed the mechanical performance of polymeric structures based on elastomeric materials. Polymeric cast films were prepared and nonwovens were manufactured in an electrospinning process. Analysis of cyclic stress-strain behavior was performed, using a universal testing machine. The uniaxial cyclic tensile experiments of the elastomeric samples yielded a non-linear elastic response due to viscoelastic behavior with hysteresis. Equilibrium of stress-strain curves was found after a specific number of cycles, for cast films and nonwovens, respectively. In conclusion, preconditioning was found obligatory for the evaluation of the mechanical performance of polymeric materials for the use as artificial leaflet material for heart valve prostheses.

  8. EFFICIENCY OF PROSTHETIC TREATMENT WITH POST RESECTION PROSTHESES WITH SOLID SUBSTITUTE PART

    Directory of Open Access Journals (Sweden)

    Ivan Gerdzhikov

    2016-08-01

    Full Text Available Aim: The aim of this study is to track the effectiveness of prosthetic treatment with post resection dentures with solid substitute part and their role in the restoration of damaged functions. Materials and methods: The study included 14 patients (9 men and 5 women with different size and location of defects in the upper jaw treated in the period 2010-2016 with post resection prostheses with a solid substitute part. The impressions were taken with irreversible hydrocolloid impression material. The prostheses were completed by heat-curing acrylic with low quantity residual monomer. The effectiveness of prosthetics was evaluated by the method of Mihaylov for both oral-nasal examination of the pressure with the device "Oronasopneumotest." For objectifying and assess the occlusal-articulation ratios was held computerized occlusal analysis with the system T-SCAN 8. Results: The results showed successful obturation and sealing of defects in all patients. It was found satisfactory recovery of the speaking function and normalization of occlusal-articulation ratios. Conclusion: The prosthetic treatment with post resection prostheses with a solid substitute part allows successful recovery of the lost speech and chewing functions, helping to restore self esteem and social rehabilitation of patients.

  9. Evaluation of Osseous Integration of PVD-Silver-Coated Hip Prostheses in a Canine Model

    Directory of Open Access Journals (Sweden)

    Gregor Hauschild

    2015-01-01

    Full Text Available Infection associated with biomaterials used for orthopedic prostheses remains a serious complication in orthopedics, especially tumor surgery. Silver-coating of orthopedic (megaprostheses 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.

  10. Interest of Flow Diversion Prostheses in the Management of Unruptured Intracranial Aneurysms

    Directory of Open Access Journals (Sweden)

    Xavier Armoiry

    2012-01-01

    Full Text Available Flow diversion prostheses represent a new endovascular approach aimed at treating patients with large wide-neck aneurysms. Our objective is to present this new technology, to review the clinical studies on efficacy, and to emphasize its current limits. Flow diversion prostheses consist of a cylinder made of a large number of braided microfilaments providing a large metallic surface when deployed and inducing a blood flow diversion outside the aneurysm. Two different brands are currently available. Clinical data supporting their efficacy are currently limited to six non comparative cohort studies that included between 18 and 107 patients. Procedural implantation was shown to be feasible in more than 90% and safe with a thirty-day mortality between 2.8 and 5.5%. Complete occlusion rates at twelve months varied between 85.7 and 100%. Even though promising, the current status of flow diversion prostheses needs further evaluation with randomized, prospective, clinical trials with comparison to conventional strategies including endovascular coiling or surgical clipping.

  11. Control Capabilities of Myoelectric Robotic Prostheses by Hand Amputees: A Scientific Research and Market Overview.

    Science.gov (United States)

    Atzori, Manfredo; Müller, Henning

    2015-01-01

    Hand amputation can dramatically affect the capabilities of a person. Cortical reorganization occurs in the brain, but the motor and somatosensorial cortex can interact with the remnant muscles of the missing hand even many years after the amputation, leading to the possibility to restore the capabilities of hand amputees through myoelectric prostheses. Myoelectric hand prostheses with many degrees of freedom are commercially available and recent advances in rehabilitation robotics suggest that their natural control can be performed in real life. The first commercial products exploiting pattern recognition to recognize the movements have recently been released, however the most common control systems are still usually unnatural and must be learned through long training. Dexterous and naturally controlled robotic prostheses can become reality in the everyday life of amputees but the path still requires many steps. This mini-review aims to improve the situation by giving an overview of the advancements in the commercial and scientific domains in order to outline the current and future chances in this field and to foster the integration between market and scientific research.

  12. Control Capabilities of Myoelectric Robotic Prostheses by Hand Amputees: A Scientific Research and Market Overview

    Directory of Open Access Journals (Sweden)

    Manfredo eAtzori

    2015-11-01

    Full Text Available Hand amputation can dramatically affect the capabilities of a person. Cortical reorganization occurs in the brain, but the motor and somatosensorial cortex can interact with the remnant muscles of the missing hand even many years after the amputation, leading to the possibility to restore the capabilities of hand amputees through myoelectric prostheses. Myoelectric hand prostheses with many degrees of freedom are commercially available and recent advances in rehabilitation robotics suggest that their natural control can be performed in real life. The first commercial products exploiting pattern recognition to recognize the movements have recently been released, however the most common control systems are still usually unnatural and must be learned through long training. Dexterous and naturally controlled robotic prostheses can become reality in the everyday life of amputees but the path still requires many steps. This mini-review aims to improve the situation by giving an overview of the advancements in the commercial and scientific domains in order to outline the current and future chances in this field and to foster the integration between market and scientific research.

  13. Neuromuscular coordination of masticatory muscles in subjects with two types of implant-supported prostheses.

    Science.gov (United States)

    Ferrario, Virgilio F; Tartaglia, Gianluca M; Maglione, Michele; Simion, Massimo; Sforza, Chiarella

    2004-04-01

    To compare the electromyographic (EMG) characteristics of masticatory muscles in patients with fixed implant-supported prostheses and implant overdentures. Nineteen subjects aged 45-79 years were examined. Fourteen were edentulous and had been successfully rehabilitated with (a) maxillary and mandibular implant-supported fixed prostheses (seven patients); (b) mandibular implant overdentures and maxillary complete dentures (seven patients). Five control subjects had natural dentition or single/partial (no more than two teeth) tooth or implant fixed dentures. Surface EMG of the masseter and temporal muscles was performed during unilateral gum chewing and during maximum teeth clenching. To reduce biological and instrumental noise, all values were standardized as percentage of a maximum clenching on cotton rolls. During clenching, temporal muscle symmetry was larger in control subjects and fixed implant-supported prosthesis patients than in overdenture patients (analysis of variance, P=0.005). No differences were found in masseter muscle symmetry or in muscular torque. Muscle activities (integrated areas of the EMG potentials over time) were significantly larger in control subjects than in implant-supported prosthesis patients (P=0.014). In both patient groups, a poor neuromuscular coordination during chewing, with altered muscular patterns, and a smaller left-right symmetry than in control subjects were found (P=0.05). No differences in masticatory frequency were found. Surface EMG analysis of clenching and chewing showed that fixed implant-supported prostheses and implant overdentures were functionally equivalent. Neuromuscular coordination during chewing was inferior to that found in subjects with natural dentition.

  14. Dental prostheses mimic the natural enamel behavior under functional loading: A review article

    Directory of Open Access Journals (Sweden)

    Ahmed A. Madfa

    2016-02-01

    Full Text Available Alumina- and zirconia-based ceramic dental restorations are designed to repair functionality as well as esthetics of the failed teeth. However, these materials exhibited several performance deficiencies such as fracture, poor esthetic properties of ceramic cores (particularly zirconia cores, and difficulty in accomplishing a strong ceramic–resin-based cement bond. Therefore, improving the mechanical properties of these ceramic materials is of great interest in a wide range of disciplines. Consequently, spatial gradients in surface composition and structure can improve the mechanical integrity of ceramic dental restorations. Thus, this article reviews the current status of the functionally graded dental prostheses inspired by the dentino-enamel junction (DEJ structures and the linear gradation in Young's modulus of the DEJ, as a new material design approach, to improve the performance compared to traditional dental prostheses. This is a remarkable example of nature's ability to engineer functionally graded dental prostheses. The current article opens a new avenue for recent researches aimed at the further development of new ceramic dental restorations for improving their clinical durability.

  15. Accelerated treatment protocols: full arch treatment with interim and definitive prostheses.

    Science.gov (United States)

    Drago, Carl

    2012-01-01

    With the advent of titanium, root form implants and osseointegration, dental treatment has undergone a metamorphosis in recent years. These new techniques enable dentists to provide anchorage for various kinds of prostheses that improve masticatory function, esthetics, and comfort for patients. Implant treatment protocols have been improved relative to implant macro- and micro-geometries, surgical and prosthetic components, and treatment times. Over the past 20 years, immediate occlusal function (also known as loading) has been established as a predictable treatment modality, provided certain specific criteria are met. In many cases, edentulous patients, crippled by the loss of their teeth, can undergo outpatient surgical and prosthetic procedures and return to a masticatory function that is near normal--sometimes after only one day of surgical and prosthetic treatment. This treatment option is also available for patients with advanced, generalized periodontal disease. Computer-assisted design/Computer-assisted manufacturing (CAD/CAM) has transformed how dental prostheses are made, offering improved accuracy, longevity, and biocompatibility; along with reduced labor costs and fewer complications than casting technologies. This article reviews the principles associated with immediate occlusal loading and illustrates one specific accelerated prosthodontic treatment protocol used to treat edentulous and partially edentulous patients with interim and definitive prostheses.

  16. High Cable Forces Deteriorate Pinch Force Control in Voluntary-Closing Body-Powered Prostheses.

    Directory of Open Access Journals (Sweden)

    Mona Hichert

    Full Text Available It is generally asserted that reliable and intuitive control of upper-limb prostheses requires adequate feedback of prosthetic finger positions and pinch forces applied to objects. Body-powered prostheses (BPPs provide the user with direct proprioceptive feedback. Currently available BPPs often require high cable operation forces, which complicates control of the forces at the terminal device. The aim of this study is to quantify the influence of high cable forces on object manipulation with voluntary-closing prostheses.Able-bodied male subjects were fitted with a bypass-prosthesis with low and high cable force settings for the prehensor. Subjects were requested to grasp and transfer a collapsible object as fast as they could without dropping or breaking it. The object had a low and a high breaking force setting.Subjects conducted significantly more successful manipulations with the low cable force setting, both for the low (33% more and high (50% object's breaking force. The time to complete the task was not different between settings during successful manipulation trials.High cable forces lead to reduced pinch force control during object manipulation. This implies that low cable operation forces should be a key design requirement for voluntary-closing BPPs.

  17. 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.

  18. 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.

  19. A comparison of the marginal vertical discrepancies of zirconium and metal ceramic posterior fixed dental prostheses before and after cementation.

    Science.gov (United States)

    Gonzalo, Esther; Suárez, Maria J; Serrano, Benjamin; Lozano, Jose F L

    2009-12-01

    Marginal discrepancies of zirconia posterior fixed dental prostheses (FDPs) fabricated using various systems have been assessed to determine the quality of the restorations and facilitate clinical use; however, studies are limited and results are ambiguous because of the sample sizes and measurement methods. The purpose of this in vitro study was to compare changes in marginal fit of posterior fixed dental prostheses of 3 zirconia systems manufactured using CAD/CAM technology and metal ceramic posterior fixed dental protheses fabricated with the conventional lost-wax technique, before and after cementation. Forty standardized master steel dies with 2 abutments simulating first mandibular premolars were fabricated to receive a posterior 3-unit FDP (from first molar to first premolar) and divided into 4 groups (n=10): Lava All-Ceramic System, Procera Bridge Zirconia, VITA In-Ceram 2000 YZ, and metal ceramic (control group). All FDPs were prepared for an internal space of 50 microm. The external marginal gap of the restorations was investigated by measuring 30 points in the middle of the buccal and lingual surfaces; therefore, 60 measurements per abutment were recorded. Measurements were made with an image analysis program on the master steel model before and after conventional cementation with a glass ionomer agent (Ketac Cem Easymix). The data obtained were statistically analyzed using 1-way ANOVA, Duncan's multiple range post hoc test, and Student's paired t test (alpha=.05). No significant differences in the vertical marginal fit before and after cementation were recorded for the analyzed groups. The marginal discrepancy of Procera abutments before and after cementation (9 +/-10 microm and 12 +/-9 microm, respectively) was less than that of the other groups. Significant differences (P=.001) were observed in marginal adaptation between Procera Bridge Zirconia and the other groups. The results of this study showed that cementation did not cause a significant

  20. SU-E-I-75: Evaluation of An Orthopedic Metal Artifact Reduction (O-MAR) Algorithm On Patients with Spinal Prostheses Near Spinal Tumors

    International Nuclear Information System (INIS)

    Shen, Z; Xia, P; Djemil, T; Klahr, P

    2014-01-01

    Purpose: To evaluate the impact of a commercial orthopedic metal artifact reduction (O-MAR) algorithm on CT image quality and dose calculation for patients with spinal prostheses near spinal tumors. Methods: A CT electron density phantom was scanned twice: with tissue-simulating inserts only, and with a titanium insert replacing solid water. A patient plan was mapped to the phantom images in two ways: with the titanium inside or outside of the spinal tumor. Pinnacle and Eclipse were used to evaluate the dosimetric effects of O-MAR on 12-bit and 16-bit CT data, respectively. CT images from five patients with spinal prostheses were reconstructed with and without O-MAR. Two observers assessed the image quality improvement from O-MAR. Both pencil beam and Monte Carlo dose calculation in iPlan were used for the patient study. The percentage differences between non-OMAR and O-MAR datasets were calculated for PTV-min, PTV-max, PTV-mean, PTV-V100, PTV-D90, OAR-V10Gy, OAR-max, and OAR-D0.1cc. Results: O-MAR improved image quality but did not significantly affect the dose distributions and DVHs for both 12-bit and 16- bit CT phantom data. All five patient cases demonstrated some degree of image quality improvement from O-MAR, ranging from small to large metal artifact reduction. For pencil beam, the largest discrepancy was observed for OARV-10Gy at 5.4%, while the other seven parameters were ≤0.6%. For Monte Carlo, the differences between non-O-MAR and O-MAR datasets were ≤3.0%. Conclusion: Both phantom and patient studies indicated that O-MAR can substantially reduce metal artifacts on CT images, allowing better visualization of the anatomical structures and metal objects. The dosimetric impact of O-MAR was insignificant regardless of the metal location, image bit-depth, and dose calculation algorithm. O-MAR corrected images are recommended for radiation treatment planning on patients with spinal prostheses because of the improved image quality and no need to modify

  1. 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

  2. Veneered zirconia inlay-retained fixed dental prostheses: 10-Year results from a prospective clinical study.

    Science.gov (United States)

    Rathmann, Friederike; Bömicke, Wolfgang; Rammelsberg, Peter; Ohlmann, Brigitte

    2017-09-01

    The purpose of this study was to evaluate the 10-year clinical performance of zirconia-based inlay-retained fixed dental prostheses (IRFDP). For replacement of a molar in 27 patients, 30 IRFDP were luted by use of different cements, Panavia F (Kuraray Europe GmbH) or Multilink Automix (Ivoclar Vivadent GmbH), with use of inlay/inlay, inlay/full-crown, or inlay/partial-crown retainers for anchorage. Frameworks were milled from yttria-stabilized zirconia (IPS e.maxZirCAD; Ivoclar Vivadent GmbH) and fully veneered with pressable ceramic (IPS e.max ZirPress; Ivoclar Vivadent GmbH). Before luting, the IRFDP were silica-coated (Rocatec; 3M Espe) and silanized (Monobond S; Ivoclar Vivadent GmbH). Complications (for example, chipping or delamination of the veneering ceramic, debonding, secondary caries, endodontic treatment, and abutment tooth fracture) and failure were reported, by use of standardized report forms, 2 weeks, 6 months, and 1, 2, and 10 years after cementation. Statistical analysis included Kaplan-Meier survival and success (complication-free survival) and Cox regression analysis (α=0.05 for all). During the 10-year observation period, the complications most often observed were chipping of the veneer and debonding. Twenty-five restorations failed and one participant dropped out. Cumulative 10-year survival and success were 12.1% and 0%, respectively. The design of the retainer, use of a dental dam, choice of cement, and location in the dental arch had no statistically significant effect on the occurrence of complications. Use of fully veneered zirconia-based IRFDP with this technique cannot be recommended. A large incidence of complications and poor survival were observed for fully veneered zirconia-based IRFDP, revealing an urgent need for further design improvements for this type of restoration. This, again, emphasizes the need for testing of new restoration designs in clinical trials before implementation in general dental practice. Copyright © 2017

  3. Interface Prostheses With Classifier-Feedback-Based User Training.

    Science.gov (United States)

    Fang, Yinfeng; Zhou, Dalin; Li, Kairu; Liu, Honghai

    2017-11-01

    It is evident that user training significantly affects performance of pattern-recognition-based myoelectric prosthetic device control. Despite plausible classification accuracy on offline datasets, online accuracy usually suffers from the changes in physiological conditions and electrode displacement. The user ability in generating consistent electromyographic (EMG) patterns can be enhanced via proper user training strategies in order to improve online performance. This study proposes a clustering-feedback strategy that provides real-time feedback to users by means of a visualized online EMG signal input as well as the centroids of the training samples, whose dimensionality is reduced to minimal number by dimension reduction. Clustering feedback provides a criterion that guides users to adjust motion gestures and muscle contraction forces intentionally. The experiment results have demonstrated that hand motion recognition accuracy increases steadily along the progress of the clustering-feedback-based user training, while conventional classifier-feedback methods, i.e., label feedback, hardly achieve any improvement. The result concludes that the use of proper classifier feedback can accelerate the process of user training, and implies prosperous future for the amputees with limited or no experience in pattern-recognition-based prosthetic device manipulation.It is evident that user training significantly affects performance of pattern-recognition-based myoelectric prosthetic device control. Despite plausible classification accuracy on offline datasets, online accuracy usually suffers from the changes in physiological conditions and electrode displacement. The user ability in generating consistent electromyographic (EMG) patterns can be enhanced via proper user training strategies in order to improve online performance. This study proposes a clustering-feedback strategy that provides real-time feedback to users by means of a visualized online EMG signal input as well

  4. Wireless link and microelectronics design for retinal prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wentai [Univ. of California, Santa Cruz, CA (United States)

    2012-02-29

    This project focuses on delivering power and data to the artificial retinal implant inside the eye and the implant microstimulator electronics which delivers the current pulses to stimulate the retinal layer to elicit visual perception. Since the use of invasive means such as tethering wires to transmit power and data results in discomfort to the patients which could eventually cause infection due to the abrasion caused by the wire and contact of the internals of the eye to the external environment, a completely wireless approach is used to transfer both power and data. Power is required inside the eye for the microelectronic implant which uses a dual voltage supply scheme (positive and negative) to deliver biphasic (anodic and cathodic) current pulses. Data in the form of digital bits from the data transmitter external to the eye, carries information about the amplitude, phase width, interphase delay, stimulation sequence for each implant electrode. The data receiver unit decodes the digital stream and the microstimulator unit generates the appropriate current stimuli. Since the external unit consisting of the power transmitter can experience coupling a variation with the power receiver due to the patient’s movements, a closed loop approach is used which varies the transmitted power dynamically to automatically compensate for such movements. This report presents the salient features of this research activities and results.

  5. Social Set Visualizer

    DEFF Research Database (Denmark)

    Flesch, Benjamin; Hussain, Abid; Vatrapu, Ravi

    2015-01-01

    -edge open source visual analytics libraries from D3.js and creation of new visualizations (ac-tor mobility across time, conversational comets etc). Evaluation of the dashboard consisting of technical testing, usability testing, and domain-specific testing with CSR students and yielded positive results.......This paper presents a state-of-the art visual analytics dash-board, Social Set Visualizer (SoSeVi), of approximately 90 million Facebook actions from 11 different companies that have been mentioned in the traditional media in relation to garment factory accidents in Bangladesh. The enterprise...

  6. Place orientation and visual construction subdomains of the Mini Mental State Examination test as predictors of rehabilitation outcome of post-acute hip-fractured patients.

    Science.gov (United States)

    Hershkovitz, Avital; Kornyukov, Natalia; Brill, Shai

    2017-11-01

    The study aimed at assessing the relationship between various Mini Mental State Examination (MMSE) subdomains and rehabilitation achievements in post-acute hip-fractured patients. Six hundred and five hip-fractured patients admitted during 2010-2013 to a post-acute geriatric rehabilitation center were included in the study. Main outcome measures were the Functional Independence Measure (FIM) instrument, the motor FIM (mFIM), the Montebello Rehabilitation Factor Score (MRFS) on the mFIM and length of stay (LOS). A logistic regression analysis tested the predictive value of MMSE subdomains for achieving a satisfactory functional gain (mFIM MRFS >30%) on operated patients admitted from community. Of all the six MMSE subdomains, place orientation and visual construction demonstrated significant predictive values for rehabilitation outcome. Patients who did not err on place orientation and visual construction MMSE domains had better probabilities [(OR 1.28, 95%CI, 1.05-1.58; p = 0.017); (OR 2.15, 95%CI, 1.28-3.59; p = 0.004), respectively] of achieving better rehabilitation achievements. Similar results were obtained for cognitively impaired patient groups [(OR 1.40 95%CI, 1.11-1.77; p = 0.005); (OR 2.47, 95%CI, 1.15-5.30; p = 0.021), respectively]. For the cognitively intact patient group, the variables with significant predictive value were time orientation and visual construction MMSE subdomains [(OR 2.26, 95%CI, 1.18-4.33; p = 0.014); (OR 2.87, 95%CI, 1.16-7.09; p = 0.022), respectively]. Post-acute hip-fractured patients scoring normally on place orientation and visual construction MMSE subdomains have a better chance of achieving favorable rehabilitation outcome. Implications for Rehabilitation Post-acute hip-fractured patients have a better chance to achieve a favorable rehabilitation outcome when scoring normally on place orientation and visual construction MMSE subdomains. Patients having difficulties in orientation and visual

  7. Randomized clinical trial of implant-supported ceramic-ceramic and metal-ceramic fixed dental prostheses: preliminary results.

    Science.gov (United States)

    Esquivel-Upshaw, Josephine F; Clark, Arthur E; Shuster, Jonathan J; Anusavice, Kenneth J

    2014-02-01

    The aim of this study was to determine the survival rates over time of implant-supported ceramic-ceramic and metal-ceramic prostheses as a function of core-veneer thickness ratio, gingival connector embrasure design, and connector height. An IRB-approved, randomized, controlled clinical trial was conducted as a single-blind pilot study involving 55 patients missing three teeth in either one or two posterior areas. These patients (34 women; 21 men; age range 52-75 years) were recruited for the study to receive a three-unit implant-supported fixed dental prosthesis (FDP). Two implants were placed for each of the 72 FDPs in the study. The implants (Osseospeed, Astra Tech), which were made of titanium, were grit blasted. A gold-shaded, custom-milled titanium abutment (Atlantis, Astra Tech), was secured to each implant body. Each of the 72 FDPs in 55 patients were randomly assigned based on one of the following options: (1) A. ceramic-ceramic (Yttria-stabilized zirconia core, pressable fluorapatite glass-ceramic, IPS e.max ZirCAD, and ZirPress, Ivoclar Vivadent) B. metal-ceramic (palladium-based noble alloy, Capricorn, Ivoclar Vivadent, with press-on leucite-reinforced glass-ceramic veneer, IPS InLine POM, Ivoclar Vivadent); (2) occlusal veneer thickness (0.5, 1.0, and 1.5 mm); (3) curvature of gingival embrasure (0.25, 0.5, and 0.75 mm diameter); and (4) connector height (3, 4, and 5 mm). FDPs were fabricated and cemented with dual-cure resin cement (RelyX, Universal Cement, 3M ESPE). Patients were recalled at 6 months, 1 year, and 2 years. FDPs were examined for cracks, fracture, and general surface quality. Recall exams of 72 prostheses revealed 10 chipping fractures. No fractures occurred within the connector or embrasure areas. Two-sided Fisher's exact tests showed no significant correlation between fractures and type of material system (p = 0.51), veneer thickness (p = 0.75), radius of curvature of gingival embrasure (p = 0.68), and connector height (p = 0

  8. Getting signals into the brain: visual prosthetics through thalamic microstimulation.

    Science.gov (United States)

    Pezaris, John S; Eskandar, Emad N

    2009-07-01

    Common causes of blindness are diseases that affect the ocular structures, such as glaucoma, retinitis pigmentosa, and macular degeneration, rendering the eyes no longer sensitive to light. The visual pathway, however, as a predominantly central structure, is largely spared in these cases. It is thus widely thought that a device-based prosthetic approach to restoration of visual function will be effective and will enjoy similar success as cochlear implants have for restoration of auditory function. In this article the authors review the potential locations for stimulation electrode placement for visual prostheses, assessing the anatomical and functional advantages and disadvantages of each. Of particular interest to the neurosurgical community is placement of deep brain stimulating electrodes in thalamic structures that has shown substantial promise in an animal model. The theory of operation of visual prostheses is discussed, along with a review of the current state of knowledge. Finally, the visual prosthesis is proposed as a model for a general high-fidelity machine-brain interface.

  9. Investigation of the dosimetric accuracy of the isocenter shifting method in prostate cancer patients with and without hip prostheses

    International Nuclear Information System (INIS)

    Hwang, Andrew B.; Kinsey, Erica; Xia Ping

    2009-01-01

    Purpose: The use of image guided radiation therapy (IGRT) enables compensation for prostate movement by shifting the treatment isocenter to track the prostate on a daily basis. Although shifting the isocenter can alter the source to skin distances (SSDs) and the effective depth of the target volume, it is commonly assumed that these changes have a negligible dosimetric effect, and therefore, the number of monitor units delivered is usually not adjusted. However, it is unknown whether or not this assumption is valid for patient with hip prostheses, which frequently contain high density materials. Methods: The authors conducted a retrospective study to investigate dosimetric effect of the isocenter shifting method for prostate patients with and without hip prostheses. For each patient, copies of the prostate volume were shifted by up to 1.5 cm from the original position to simulate prostate movement in 0.5 cm increments. Subsequently, 12 plans were created for each patient by creating a copy of the original plan for each prostate position with the isocenter shifted to track the position of the shifted prostate. The dose to the prostate was then recalculated for each plan. For patients with hip prostheses, plans were created both with and without lateral beam angles entering through the prostheses. Results: Without isocenter shifting to compensate for prostate motion of 1.5 cm, the dose to the 95% of the prostate (D-95%) changed by an average of 30% and by up to 64%. This was reduced to less than 3% with the isocenter shifting method. It was found that for patients with hip prostheses, this technique worked best for treatment plans that avoided beam angles passing through the prostheses. Conclusions: The results demonstrated that the isocenter shifting method can accurately deliver dose to the prostate even in patients with hip prostheses.

  10. Dose attenuation effect of hip prostheses in a 9-MV photon beam. Commercial treatment planning system versus Monte Carlo calculations

    International Nuclear Information System (INIS)

    Mesbahi, A.; Nejad, F.S.

    2007-01-01

    The purpose of this study was to investigate the dosimetric effect of various hip prostheses on pelvis lateral fields treated by a 9-MV photon beam using Monte Carlo (MC) and effective path-length (EPL) methods. The head of the Neptun 10 pc linac was simulated using the MCNP4C MC code. The accuracy of the MC model was evaluated using measured dosimetric features including depth dose values and dose profiles in a water phantom. The Alfard treatment planning system (TPS) was used for EPL calculations. A virtual water phantom with dimensions of 30 x 30 x 30 cm 3 and a cube with dimensions of 4 x 4 x 4 cm 3 made of various metals centered in 12 cm depth was used for MC and EPL calculations. Various materials including titanium, Co-Cr-Mo, and steel alloys were used as hip prostheses. Our results showed significant attenuation in absorbed dose for points after and inside the prostheses. Attenuations of 32%, 54% and 55% were seen for titanium, Co-Cr-Mo, and steel alloys, respectively, at a distance of 5 cm from the prosthesis. Considerable dose increase (up to 18%) was found at the water-prosthesis interface due to back-scattered electrons using the MC method. The results of EPL calculations for the titanium implant were comparable to the MC calculations. This method, however, was not able to predict the interface effect or calculate accurately the absorbed dose in the presence of the Co-Cr-Mo and steel prostheses. The dose perturbation effect of hip prostheses is significant and cannot be predicted accurately by the EPL method for Co-Cr-Mo or steel prostheses. The use of MC-based TPS is recommended for treatments requiring fields passing through hip prostheses. (author)

  11. Efficiency of voluntary closing hand and hook prostheses

    NARCIS (Netherlands)

    Smit, G.; Plettenburg, D.H.

    2010-01-01

    The Delft Institute of Prosthetics and Orthotics has started a research program to develop an improved voluntary closing, body-powered hand prosthesis. Five commercially available voluntary closing terminal devices were mechanically tested: three hands [Hosmer APRL VC hand, Hosmer Soft VC Male hand,

  12. Role of thirst and visual barriers in the differential behavior displayed by streptozotocin-treated rats in the elevated plus-maze and the open field test.

    Science.gov (United States)

    Rebolledo-Solleiro, Daniela; Crespo-Ramírez, Minerva; Roldán-Roldán, Gabriel; Hiriart, Marcia; Pérez de la Mora, Miguel

    2013-08-15

    Conflicting results have been obtained by several groups when studying the effects of streptozotocin (STZ)-treated rats in the elevated plus-maze (EPM). Since thirst is a prominent feature in STZ-induced diabetic-like condition, we studied whether the walls of the closed arms of the EPM, by limiting the search for water in the environment, may contribute to the observed differential behavioral outcomes. The aim of this study was to ascertain whether visual barriers within the EPM have an influence on the behavior of STZ-treated rats in this test of anxiety. A striking similarity between STZ-treated (50 mg/kg, i.p., in two consecutive days) and water deprived rats (72 h) was found in exploratory behavior in the EPM, showing an anxiolytic-like profile. However the anxiolytic response of STZ-treated rats exposed to the EPM shifts into an anxiogenic profile when they are subsequently tested in the open-field test, which unlike the EPM is devoid of visual barriers. Likewise, water deprived rats (72 h) also showed an anxiogenic profile when they were exposed to the open-field test. Our results indicate that experimental outcomes based on EPM observations can be misleading when studying physiological or pathological conditions, e.g. diabetes, in which thirst may increase exploratory behavior. © 2013.

  13. 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)

  14. Marginal Vertical Discrepancies of Monolithic and Veneered Zirconia and Metal-Ceramic Three-Unit Posterior Fixed Dental Prostheses.

    Science.gov (United States)

    Lopez-Suarez, Carlos; Gonzalo, Esther; Pelaez, Jesus; Serrano, Benjamin; Suarez, Maria J

    2016-01-01

    The aim of this study was to investigate and compare the marginal fit of posterior fixed dental prostheses (FDPs) made of monolithic and veneered computer-aided design/computer-assisted manufacture (CAD/CAM) zirconia ceramic with metal-ceramic posterior FDPs. Thirty standardized steel dies were prepared to receive posterior three-unit FDPs. Specimens were randomly divided into three groups (n = 10): (1) metal-ceramic (control group), (2) veneered zirconia, and (3) monolithic zirconia. All FDPs were cemented using a glass-ionomer cement. The specimens were subjected to thermal cycling (5°C to 55°C). A scanning electron microscope (SEM) with a magnification of ×500 was used for measurements. The data were statistically analyzed using one-way analysis of variance and paired t test. Both zirconia groups showed similar vertical marginal discrepancies, and no significant differences (P = .661) in marginal adaptation were observed among the groups. No differences were observed in either group in marginal discrepancies between surfaces or abutments. Monolithic zirconia posterior FDPs exhibit similar vertical marginal discrepancies to veneered zirconia posterior FDPs. No influence of localization measurements was observed.

  15. Feature extraction using extrema sampling of discrete derivatives for spike sorting in implantable upper-limb neural prostheses.

    Science.gov (United States)

    Zamani, Majid; Demosthenous, Andreas

    2014-07-01

    Next generation neural interfaces for upper-limb (and other) prostheses aim to develop implantable interfaces for one or more nerves, each interface having many neural signal channels that work reliably in the stump without harming the nerves. To achieve real-time multi-channel processing it is important to integrate spike sorting on-chip to overcome limitations in transmission bandwidth. This requires computationally efficient algorithms for feature extraction and clustering suitable for low-power hardware implementation. This paper describes a new feature extraction method for real-time spike sorting based on extrema analysis (namely positive peaks and negative peaks) of spike shapes and their discrete derivatives at different frequency bands. Employing simulation across different datasets, the accuracy and computational complexity of the proposed method are assessed and compared with other methods. The average classification accuracy of the proposed method in conjunction with online sorting (O-Sort) is 91.6%, outperforming all the other methods tested with the O-Sort clustering algorithm. The proposed method offers a better tradeoff between classification error and computational complexity, making it a particularly strong choice for on-chip spike sorting.

  16. Marginal and internal fit of cobalt-chromium fixed dental prostheses generated from digital and conventional impressions.

    Science.gov (United States)

    Svanborg, Per; Skjerven, Henrik; Carlsson, Pablo; Eliasson, Alf; Karlsson, Stig; Ortorp, Anders

    2014-01-01

    Objectives. Digital impressions are increasingly used and have the potential to avoid the problem of inaccurate impressions. Only a few studies to verify the accuracy of digital impressions have been performed. The purpose of this study was to compare the marginal and internal fit of 3-unit tooth supported fixed dental prostheses (FDPs) fabricated from digital and conventional impressions. Methods. Ten FDPs were produced from digital impressions using the iTero system and 10 FDPs were produced using vinyl polysiloxane (VPS) impression material. A triple-scan protocol and CAD software were used for measuring and calculating discrepancies of the FDPs at 3 standard areas: mean internal discrepancy, absolute marginal gap, and cervical area discrepancy. The Mann-Whitney U test was used for analyzing the results. Results. For conventional and digital impressions, respectively, FDPs had an absolute marginal gap of 147  μ m and 142  μ m, cervical area discrepancy of 69  μ m and 44  μ m, and mean internal discrepancy of 117  μ m and 93  μ m. The differences were statistically significant in the cervical and internal areas (P digital impression technique is more exact and can generate 3-unit FDPs with a significantly closer fit compared to the VPS technique.

  17. Marginal and Internal Fit of Cobalt-Chromium Fixed Dental Prostheses Generated from Digital and Conventional Impressions

    Directory of Open Access Journals (Sweden)

    Per Svanborg

    2014-01-01

    Full Text Available Objectives. Digital impressions are increasingly used and have the potential to avoid the problem of inaccurate impressions. Only a few studies to verify the accuracy of digital impressions have been performed. The purpose of this study was to compare the marginal and internal fit of 3-unit tooth supported fixed dental prostheses (FDPs fabricated from digital and conventional impressions. Methods. Ten FDPs were produced from digital impressions using the iTero system and 10 FDPs were produced using vinyl polysiloxane (VPS impression material. A triple-scan protocol and CAD software were used for measuring and calculating discrepancies of the FDPs at 3 standard areas: mean internal discrepancy, absolute marginal gap, and cervical area discrepancy. The Mann-Whitney U test was used for analyzing the results. Results. For conventional and digital impressions, respectively, FDPs had an absolute marginal gap of 147 μm and 142 μm, cervical area discrepancy of 69 μm and 44 μm, and mean internal discrepancy of 117 μm and 93 μm. The differences were statistically significant in the cervical and internal areas (P<0.001. Significance. The results indicated that the digital impression technique is more exact and can generate 3-unit FDPs with a significantly closer fit compared to the VPS technique.

  18. Corrosion of dental magnet attachments for removable prostheses on teeth and implants.

    Science.gov (United States)

    Boeckler, Arne F; Ehring, Carolin; Morton, Dean; Geis-Gerstorfer, Jürgen; Setz, Juergen M

    2009-06-01

    For a long time, the use of magnets for the anchorage of dental prostheses failed due to lack of biocompatibility and the magnets' high susceptibility to corrosion in the mouth. These facts make encapsulation of the magnetic alloy with a corrosion-resistant, tight, and functionally firm sealing necessary. Due to different products and analysis methods, it is not feasible to compare the findings for contemporary products with the sparse and rather old test results in the literature. Therefore, the aim of this study was the standardized control and the comparison of the corrosion behavior of modern magnetic attachments for use on teeth and dental implants. Thirty-seven components of magnetic attachments on implants and natural teeth from different alloys (NdFeB, SmCo, Ti, CrMoMnTiFe, etc.) as delivered by the manufacturers or fabricated according to their instructions were examined for their corrosion behavior using the statical immersion analysis (ISO 10271:2001). Four specimens of every product with the same design were used. An uncased SmCo magnet served as control. Analyses after 1, 4, 7, and 28 days of the storage in corrosion solution were made. The eluate was examined quantitatively on the alloy components of the respective component with the help of optical emission spectrometry (microg/cm(2)). The results were compared to the requirements of ISO standard 22674:2006. In addition, existing corrosion products were also defined in the solution after 28 days. The results were analyzed descriptively and statistically to determine possible significant differences (t-test and Mann-Whitney-Wilcoxon rank-sums test; p keeper), Cr (1.18, Magfit DX 800 keeper), Pd (0.21, Direct System Keeper), Ni (0.18, WR-Magnet S3 small), Co (0.12, Direct System Keeper), and Ti (0.09, Magna Cap - Mini). After 28 days, the analyzed ion release increased non-uniformly: Fe (31.92, Magfit DX 800 Keeper), Cr (6.65, Magfit DX 800 Keeper), Pd (18.19, Direct System Keeper), Ni (0.61, WR

  19. 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.

  20. Sport prostheses and prosthetic adaptations for the upper and lower limb amputees: an overview of peer reviewed literature.

    Science.gov (United States)

    Bragaru, Mihai; Dekker, Rienk; Geertzen, Jan H B

    2012-09-01

    Sport prostheses are used by both upper- and lower-limb amputees while participating in sports and other physical activities. Although the number of these devices has increased over the past decade, no overview of the peer reviewed literature describing them has been published previously. Such an overview will allow specialists to choose appropriate prostheses based on available scientific evidence rather than on personal experience or preference. To provide an overview of the sport prostheses as they are described by the papers published in peer reviewed literature. Literature review. Four electronic databases were searched using free text and Medical Subject Headings (MESH) terms. Papers were included if they concerned a prosthesis or a prosthetic adaptation used in sports. Papers were excluded if they did not originate from peer reviewed sources, if they concerned prostheses for body parts other than the upper or lower limbs, if they concerned amputations distal to the wrist or ankle, or if they were written in a language other than English. Twenty-four papers were included in this study. The vast majority contained descriptive data and consisted of expert opinions and technical notes. Data concerning the energy efficiency, technical characteristics and special mechanical properties of prostheses or prosthetic adaptations for sports, other than running, are scarce.

  1. The effects of repeated testing, simulated malingering, and traumatic brain injury on high-precision measures of simple visual reaction time

    Directory of Open Access Journals (Sweden)

    David L Woods

    2015-11-01

    Full Text Available Simple reaction time (SRT, the latency to respond to a stimulus, has been widely used as a basic measure of processing speed. In the current experiments, we examined clinically-relevant properties of a new SRT test that presents visual stimuli to the left or right hemifield at varying stimulus onset asynchronies. Experiment 1 examined test-retest reliability in participants who underwent three test sessions at weekly intervals. In the first test, log-transformed (log-SRT z-scores, corrected for the influence of age and computer-use, were well predicted by regression functions derived from a normative population of 189 control participants. Test-retest reliability of log-SRT z-scores was measured with an intraclass correlation coefficient (ICC = 0.83 and equaled or exceeded those of other SRT tests and other widely used tests of processing speed that are administered manually. No significant learning effects were observed across test sessions. Experiment 2 investigated the same participants when instructed to malinger during a fourth testing session: 94% showed abnormal log-SRT z-scores, with 83% producing log-SRT z-scores exceeding a cutoff of 3.0, a degree of abnormality never seen in full-effort conditions. Thus, a log-SRT z-score cutoff of 3.0 had a sensitivity (83% and specificity (100% that equaled or exceeded that of existing symptom validity tests. We argue that even expert malingerers, fully informed of the malingering-detection metric, would be unable to successfully feign impairments on the SRT test because of the precise control of SRT latencies that would be required. Experiment 3 investigated 26 patients with traumatic brain injury (TBI tested more than one year post-injury. The 22 patients with mild TBI showed insignificantly faster SRTs than controls, but a small group of four patients with severe TBI showed slowed SRTs. Simple visual reaction time is a reliable measure of processing speed that is sensitive to the effects of

  2. Long-term memory for verbal and visual information in Down syndrome and Williams syndrome: performance on the Doors and People test.

    Science.gov (United States)

    Jarrold, Christopher; Baddeley, Alan D; Phillips, Caroline

    2007-02-01

    Previous studies have suggested that Williams syndrome and Down syndrome may be associated with specific short-term memory deficits. Individuals with Williams syndrome perform relatively poorly on tests of visuo-spatial short-term memory and individuals with Down syndrome show a relative deficit on verbal short-term memory tasks. However, these patterns of impairments may reflect the impact of generally impaired visuo-spatial processing skills in Williams syndrome, and verbal abilities in Down syndrome. The current study explored this possibility by assessing long-term memory among 15 individuals with Williams syndrome and 20 individuals with Down syndrome using the Doors and People test, a battery which assesses recall and recognition of verbal and visual information. Individuals' performance was standardised for age and level of intellectual ability with reference to that shown by a sample of 110 typically developing children. The results showed that individuals with Down syndrome have no differential deficits in long-term memory for verbal information, implying that verbal short-term memory deficits in this population are relatively selective. Instead both individuals with Down syndrome and with Williams syndrome showed some evidence of relatively poor performance on tests of long-term memory for visual information. It is therefore possible that visuo-spatial short-term memory deficits that have previously been demonstrated in Williams syndrome may be secondary to more general problems in visuo-spatial processing in this population.

  3. 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......, and HPV-testing to detect cytologically diagnosed high grade lesions or cancer (HSIL+). Women from different areas in Tanzania were invited by public announcement to cervical cancer screening organized by Ocean Road Cancer Institute (Dar-es-Salaam). A total of 3,767 women were enrolled. Women underwent...

  4. 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.

  5. A biodegradable gentamicin-hydroxyapatite-coating for infection prophylaxis in cementless hip prostheses

    Directory of Open Access Journals (Sweden)

    D Neut

    2015-01-01

    Full Text Available A degradable, poly (lactic-co-glycolic acid (PLGA, gentamicin-loaded prophylactic coating for hydroxyapatite (HA-coated cementless hip prostheses is developed with similar antibacterial efficacy as offered by gentamicin-loaded cements for fixing traditional, cemented prostheses in bone. We describe the development pathway, from in vitro investigation of antibiotic release and antibacterial properties of this PLGA-gentamicin-HA-coating in different in vitro models to an evaluation of its efficacy in preventing implant-related infection in rabbits. Bone in-growth in the absence and presence of the coating was investigated in a canine model. The PLGA-gentamicin-HA-coating showed high-burst release, with antibacterial efficacy in agar-assays completely disappearing after 4 days, minimising risk of inducing antibiotic resistance. Gentamicin-sensitive and gentamicin-resistant staphylococci were killed by the antibiotic-loaded coating, in a simulated prosthesis-related interfacial gap. PLGA-gentamicin-HA-coatings prevented growth of bioluminescent staphylococci around a miniature-stem mounted in bacterially contaminated agar, as observed using bio-optical imaging. PLGA-gentamicin-HA-coated pins inserted in bacterially contaminated medullary canals in rabbits caused a statistically significant reduction in infection rates compared to HA-coated pins without gentamicin. Bone ingrowth to PLGA-gentamicin-HA-coated pins, in condylar defects of Beagle dogs was not impaired by the presence of the degradable, gentamicin-loaded coating. In conclusion, the PLGA-gentamicin-HA-coating constitutes an effective strategy for infection prophylaxis in cementless prostheses.

  6. [Clinical characteristics of the Soviet low-profile heart valve prostheses EMIKS and LIKS].

    Science.gov (United States)

    Tsukerman, G I; Dobrova, N B; Faminskiĭ, D O; Pomortseva, L V; Gvakhariia, I N; Chigogidze, N A; Zaretskiĭ, Iu V

    1989-01-01

    The present work is devoted to the clinical assessment of the Soviet-made cardiac valve prostheses 'EMIKS' and 'LIKS'. From 1983 to May 1, 1988, 632 prostheses were implanted to 508 patients. A group of 348 patients were assessed: 139 after mitral (M) replacement, 130 after aortal (A) replacement, and 79 after mitral-aortal (M+A) replacement. Hospital mortality rate was: in M group--4.3 per cent, in A group--5.3 per cent, in M+A group--8.8 per cent. Survival rate on the fifth postoperative year was: in M group--89.5 +/- 9.2 per cent, in a group--90.0 +/- 4.2 per cent, in M+A group--91.0 +/- 6.2 per cent, the stability of the good results being 85.5 +/- 7.2, 79.5 +/- 6.2, and 75.0 +/- 9.1 per cent, respectively. At year 5 of the follow-up, patient numbers without thromboembolic complications amounted to 95.0 +/- 4.7 per cent in M group, 95.5 +/- 4.2 per cent in A group, and 85.0 +/- 9.1 in M+A group. 95.1 per cent patients belong to functional classes I and II. In mitral replacement, the mean 'EMIKS' gradient was 4.2 +/- 0.58 mm Hg, the 'LIKS' one--4.58 +/- 0.62 mm Hg. Intravascular hemolysis was not observed. The 'EMIKS' and 'LIKS' prostheses match the models produced in other countries. No significant differences between the two models were found.

  7. Whole-body angular momentum during stair walking using passive and powered lower-limb prostheses.

    Science.gov (United States)

    Pickle, Nathaniel T; Wilken, Jason M; Aldridge, Jennifer M; Neptune, Richard R; Silverman, Anne K

    2014-10-17

    Individuals with a unilateral transtibial amputation have a greater risk of falling compared to able-bodied individuals, and falling on stairs can lead to serious injuries. Individuals with transtibial amputations have lost ankle plantarflexor muscle function, which is critical for regulating whole-body angular momentum to maintain dynamic balance. Recently, powered prostheses have been designed to provide active ankle power generation with the goal of restoring biological ankle function. However, the effects of using a powered prosthesis on the regulation of whole-body angular momentum are unknown. The purpose of this study was to use angular momentum to evaluate dynamic balance in individuals with a transtibial amputation using powered and passive prostheses relative to able-bodied individuals during stair ascent and descent. Ground reaction forces, external moment arms, and joint powers were also investigated to interpret the angular momentum results. A key result was that individuals with an amputation had a larger range of sagittal-plane angular momentum during prosthetic limb stance compared to able-bodied individuals during stair ascent. There were no significant differences in the frontal, transverse, or sagittal-plane ranges of angular momentum or maximum magnitude of the angular momentum vector between the passive and powered prostheses during stair ascent or descent. These results indicate that individuals with an amputation have altered angular momentum trajectories during stair walking compared to able-bodied individuals, which may contribute to an increased fall risk. The results also suggest that a powered prosthesis provides no distinct advantage over a passive prosthesis in maintaining dynamic balance during stair walking. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Validation Test Report For The CRWMS Analysis and Logistics Visually Interactive Model Version 3.0, 10074-Vtr-3.0-00

    International Nuclear Information System (INIS)

    Gillespie, S.

    2000-01-01

    This report describes the tests performed to validate the CRWMS ''Analysis and Logistics Visually Interactive'' Model (CALVIN) Version 3.0 (V3.0) computer code (STN: 10074-3.0-00). To validate the code, a series of test cases was developed in the CALVIN V3.0 Validation Test Plan (CRWMS M and O 1999a) that exercises the principal calculation models and options of CALVIN V3.0. Twenty-five test cases were developed: 18 logistics test cases and 7 cost test cases. These cases test the features of CALVIN in a sequential manner, so that the validation of each test case is used to demonstrate the accuracy of the input to subsequent calculations. Where necessary, the test cases utilize reduced-size data tables to make the hand calculations used to verify the results more tractable, while still adequately testing the code's capabilities. Acceptance criteria, were established for the logistics and cost test cases in the Validation Test Plan (CRWMS M and O 1999a). The Logistics test cases were developed to test the following CALVIN calculation models: Spent nuclear fuel (SNF) and reactivity calculations; Options for altering reactor life; Adjustment of commercial SNF (CSNF) acceptance rates for fiscal year calculations and mid-year acceptance start; Fuel selection, transportation cask loading, and shipping to the Monitored Geologic Repository (MGR); Transportation cask shipping to and storage at an Interim Storage Facility (ISF); Reactor pool allocation options; and Disposal options at the MGR. Two types of cost test cases were developed: cases to validate the detailed transportation costs, and cases to validate the costs associated with the Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M and O) and Regional Servicing Contractors (RSCs). For each test case, values calculated using Microsoft Excel 97 worksheets were compared to CALVIN V3.0 scenarios with the same input data and assumptions. All of the test case results compare with

  9. Early rehabilitation of facial defects using interim removable prostheses: A clinical case report

    Directory of Open Access Journals (Sweden)

    Vivekanandhan Ramkumar

    2013-01-01

    Full Text Available Surgical resection of neoplasms or malformations of the face may result in defects that are not amenable to immediate surgical reconstruction. Such defects can have a severe adverse effect on patient perceptions of body image and self-esteem. In these cases, the use of an interim removable facial prosthesis can offer a rapid alternative treatment solution. The patient may then resume social interactions more comfortably while permitting easy access to the facial defect to observe tissue healing while awaiting definitive rehabilitation. This article presents a case report describing the use of interim nasal prostheses to provide rapid patient rehabilitation of facial defects.

  10. High-density EMG e-textile systems for the control of active prostheses

    DEFF Research Database (Denmark)

    Farina, Dario; Lorrain, Thomas; Negro, Francesco

    2010-01-01

    Myoelectric control of active prostheses requires electrode systems that are easy to apply for daily repositioning of the electrodes by the user. In this study we propose the use of Smart Fabric and Interactive Textile (SFIT) systems as an alternative solution for recording high-density EMG signa...... classified with linear discriminant analysis. The average classification accuracy for the nine tasks was 89.1 1.9 %. These results show that SFIT systems can be used as an effective way for muscle-machine interfacing....

  11. Brachial plexus injury management through upper extremity amputation with immediate postoperative prostheses.

    Science.gov (United States)

    Malone, J M; Leal, J M; Underwood, J; Childers, S J

    1982-02-01

    Management of patients with brachial plexus injuries requires a team approach so that all aspects of their care are addressed simultaneously. This report examines elective amputation and prosthetic rehabilitation in a patient with brachial plexus avulsion of the left arm. The best possibility for good prosthetic rehabilitation is the early application of prosthetic devices with intensive occupational therapy. Using this type of approach, we have achieved significant improvement in amputation rehabilitation of upper extremity amputees treated with immediate postoperative conventional electric and myoelectric prostheses.

  12. 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

  13. 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…

  14. Development of an Air Pneumatic Suspension System for Transtibial Prostheses

    Directory of Open Access Journals (Sweden)

    Gholamhossein Pirouzi

    2014-09-01

    Full Text Available The suspension system and socket fitting of artificial limbs have major roles and vital effects on the comfort, mobility, and satisfaction of amputees. This paper introduces a new pneumatic suspension system that overcomes the drawbacks of current suspension systems in donning and doffing, change in volume during daily activities, and pressure distribution in the socket-stump interface. An air pneumatic suspension system (APSS for total-contact sockets was designed and developed. Pistoning and pressure distribution in the socket-stump interface were tested for the new APSS. More than 95% of the area between each prosthetic socket and liner was measured using a Tekscan F-Scan pressure measurement which has developed matrix-based pressure sensing systems. The variance in pressure around the stump was 8.76 kPa. APSS exhibits less pressure concentration around the stump, improved pressure distribution, easy donning and doffing, adjustability to remain fitted to the socket during daily activities, and more adaptability to the changes in stump volume. The volume changes were adjusted by utility of air pressure sensor. The vertical displacement point and reliability of suspension were assessed using a photographic method. The optimum pressure in every level of loading weight was 55 kPa, and the maximum displacement was 6 mm when 90 N of weight was loaded.

  15. Stress analysis in oral obturator prostheses: imaging photoelastic

    Science.gov (United States)

    Pesqueira, Aldiéris Alves; Goiato, Marcelo Coelho; dos Santos, Daniela Micheline; Haddad, Marcela Filié; Andreotti, Agda Marobo; Moreno, Amália

    2013-06-01

    Maxillary defects resulting from cancer, trauma, and congenital malformation affect the chewing efficiency and retention of dentures in these patients. The use of implant-retained palatal obturator dentures has improved the self-esteem and quality of life of several subjects. We evaluate the stress distribution of implant-retained palatal obturator dentures with different attachment systems by using the photoelastic analysis images. Two photoelastic models of the maxilla with oral-sinus-nasal communication were fabricated. One model received three implants on the left side of the alveolar ridge (incisive, canine, and first molar regions) and the other did not receive implants. Afterwards, a conventional palatal obturator denture (control) and two implant-retained palatal obturator dentures with different attachment systems (O-ring; bar-clip) were constructed. Models were placed in a circular polariscope and a 100-N axial load was applied in three different regions (incisive, canine, and first molar regions) by using a universal testing machine. The results were photographed and analyzed qualitatively using a software (Adobe Photoshop). The bar-clip system exhibited the highest stress concentration followed by the O-ring system and conventional denture (control). Images generated by the photoelastic method help in the oral rehabilitator planning.

  16. Four-unit fixed dental prostheses replacing the maxillary incisors supported by two narrow-diameter implants - a five-year case series.

    Science.gov (United States)

    Moráguez, Osvaldo; Vailati, Francesca; Grütter, Linda; Sailer, Irena; Belser, Urs C

    2017-07-01

    (1) To determine the survival rate of 10 four-unit fixed dental prostheses (FDPs) replacing the four maxillary incisors, supported by 20 narrow-diameter implants (NDIs), (2) to assess the incidence of mechanical and biological complications, and (3) to evaluate bone level changes longitudinally after final FDP insertion. Ten patients (six women, four men), mean age 49.4 ± 12.6 years, were treated with a four-unit anterior maxillary FDP (six screw-retained; four cemented). Biological parameters, eventual technical complications, radiographic measurements, and study casts were assessed at 1 (baseline), 3, and 5 years after implant placement. A multilevel logistic regression test was performed on clinical parameters and bone level changes (significance level P four-unit FDP to replace the four missing maxillary incisors may be considered a predictable treatment modality. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Efficacy of cleansing agents in killing microorganisms in mixed species biofilms present on silicone facial prostheses-an in vitro study

    NARCIS (Netherlands)

    Ariani, Nina; Visser, Anita; Teulings, Margot R. I. M.; Dijk, Melissa; Rahardjo, Tri Budi W.; Vissink, Arjan; van der Mei, Henny C.

    2015-01-01

    The purpose of this study was to assess the efficacy of different cleansing agents in killing mixed species biofilms on silicone facial prostheses. Two bacterial and three yeast strains, isolated from silicone facial prostheses, were selected for the mixed species biofilms. A variety of agents used

  18. Clinical and Radiographic Assessment of Reasons for Replacement of Metal- Ceramic Fixed Dental Prostheses in Patients Referring to Dental School.

    Science.gov (United States)

    Al Refai, Roa'a; Saker, Samah

    2018-01-01

    The expected length of service and reasons for fixed dental prostheses (FDPs) replacement are a frequent inquiry by patients while the answers were mainly based on studies reports that was conducted outside the middle east region. This clinical and radiographic survey was constructed to assess and survey clinically and radiographically the reasons of replacement of metal-ceramic fixed dental prostheses, amongst patients reporting at dental school in Taibah University. Between January and May 2016, 151 patients were recruited for this study. Interview (include questions pertained to the length of service of the prosthesis, the nature of complaint as told by patient in her own words), clinical examination, intra-oral photographs, and periapical radiographs, were done by the researchers. The parameters assessed were secondary caries, open margins, loss of retention, failure of endodontic treatment of the abutment and periodontal diseases. A total number of 249 failed fixed dental prostheses were evaluated. Of which 180 (39.7%) were single crowns, 159 (35.0%) were retainers and 117 (25.8%) were pontics in 69 fixed partial denture. The most common reason for replacement of fixed restorations was periodontal diseases affecting 92.8% of all types' restorations, followed by defective margin in 90.4% of examined restoration, poor aesthetic in 88% of restorations, while periapical involvement was found in 85.5% of fixed dental prosthesis. The survival rates of fixed prostheses were not predictable, and no association was found between number of years in service and the number of restorations. The most common reasons for replacing single unit fixed dental prostheses are periodontal diseases and periapical involvement, while defective margins and poor aesthetic mainly associated with multi-unit fixed dental prostheses. Key words: Failure, Fixed dental prosthesis, Survival, Replacement.

  19. 19 mm sized bileaflet valve prostheses' flow field investigated by bidimensional laser Doppler anemometry (part II: maximum turbulent shear stresses)

    Science.gov (United States)

    Barbaro, V; Grigioni, M; Daniele, C; D'Avenio, G; Boccanera, G

    1997-11-01

    The investigation of the flow field generated by cardiac valve prostheses is a necessary task to gain knowledge on the possible relationship between turbulence-derived stresses and the hemolytic and thrombogenic complications in patients after valve replacement. The study of turbulence flows downstream of cardiac prostheses, in literature, especially concerns large-sized prostheses with a variable flow regime from very low up to 6 L/min. The Food and Drug Administration draft guidance requires the study of the minimum prosthetic size at a high cardiac output to reach the maximum Reynolds number conditions. Within the framework of a national research project regarding the characterization of cardiovascular endoprostheses, an in-depth study of turbulence generated downstream of bileaflet cardiac valves is currently under way at the Laboratory of Biomedical Engineering of the Istituto Superiore di Sanita. Four models of 19 mm bileaflet valve prostheses were used: St Jude Medical HP, Edwards Tekna, Sorin Bicarbon, and CarboMedics. The prostheses were selected for the nominal Tissue Annulus Diameter as reported by manufacturers without any assessment of valve sizing method, and were mounted in aortic position. The aortic geometry was scaled for 19 mm prostheses using angiographic data. The turbulence-derived shear stresses were investigated very close to the valve (0.35 D0), using a bidimensional Laser Doppler anemometry system and applying the Principal Stress Analysis. Results concern typical turbulence quantities during a 50 ms window at peak flow in the systolic phase. Conclusions are drawn regarding the turbulence associated to valve design features, as well as the possible damage to blood constituents.

  20. Student Perceptions of Sectional CT/MRI Use in Teaching Veterinary Anatomy and the Correlation with Visual Spatial Ability: A Student Survey and Mental Rotations Test.

    Science.gov (United States)

    Delisser, Peter J; Carwardine, Darren

    2017-11-29

    Diagnostic imaging technology is becoming more advanced and widely available to veterinary patients with the growing popularity of veterinary-specific computed tomography (CT) and magnetic resonance imaging (MRI). Veterinary students must, therefore, be familiar with these technologies and understand the importance of sound anatomic knowledge for interpretation of the resultant images. Anatomy teaching relies heavily on visual perception of structures and their function. In addition, visual spatial ability (VSA) positively correlates with anatomy test scores. We sought to assess the impact of including more diagnostic imaging, particularly CT/MRI, in the teaching of veterinary anatomy on the students' perceived level of usefulness and ease of understanding content. Finally, we investigated survey answers' relationship to the students' inherent baseline VSA, measured by a standard Mental Rotations Test. Students viewed diagnostic imaging as a useful inclusion that provided clear links to clinical relevance, thus improving the students' perceived benefits in its use. Use of CT and MRI images was not viewed as more beneficial, more relevant, or more useful than the use of radiographs. Furthermore, students felt that the usefulness of CT/MRI inclusion was mitigated by the lack of prior formal instruction on the basics of CT/MRI image generation and interpretation. To be of significantly greater use, addition of learning resources labeling relevant anatomy in tomographical images would improve utility of this novel teaching resource. The present study failed to find any correlation between student perceptions of diagnostic imaging in anatomy teaching and their VSA.

  1. Adaptación en población infantil del test neuropsicológico de aprendizaje y memoria visual (DCS: neurodesarrollo de la memoria figurativa

    Directory of Open Access Journals (Sweden)

    Pedro Alberto González-Pérez

    2013-12-01

    Full Text Available El desarrollo de instrumentos destinados a evaluar las habilidades de aprendizaje y memoria visual ha sido limitado. De ello se deduce la escasez de estudios sobre el desarrollo neuropsicológico de esta función. El Test Neuropsicológico de Aprendizaje y Memoria Visual (DCS puede contribuir a solventar esta situación. El objetivo central de este trabajo ha sido la adaptación a una población infantil española de una forma concreta de administración de la citada prueba y el estudio del patrón de desarrollo neuropsicológico del aprendizaje y la memoria para material no-verbal. Se administró la prueba a 79 niños con edades comprendidas entre los 6 y 12 años. Los resultados evidenciaron la adecuación de las versiones paralelas de administración, la inexistencia de diferencias en función del sexo y una coherente consistencia interna de la prueba en torno a dos factores, uno relacionado con las estrategias de aprendizaje y evocación libre y otro relacionado con el recuerdo por reconocimiento. Se objetivó además un incremento significativo en el rendimiento en el test en función de la edad.

  2. 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 pain or dizziness handicap. These findings are inconsistent with other measures of cervical 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.

  3. 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

    Many applications of small Unmanned Aircraft System (UAS) have been envisioned. These include surveillance of key assets such as pipelines, rail, or electric wires, deliveries, search and rescue, traffic monitoring, videography, and precision agriculture. These operations are likely to occur in the same airspace in the presence of many static and dynamic constraints such as airports, and high wind areas. Therefore, operations of small UAS need to be managed to ensure safety and operation efficiency is maintained. NASA has advanced a concept for UAS Traffic Management (UTM) and has initiated a research effort to refine that concept and develop operational and system requirements. A UTM research platform is in development and flight test activities to evaluate core functions and key assumptions focusing exclusively on UAS operations in different environments are underway. This seminar will present lessons learned from a recent flight test focused on enabling operations of multiple UAS in lower-risk environments within and beyond visual line of sight (BVLOS).

  4. Human Visual System as a Double-Slit Single Photon Interference Sensor: A Comparison between Modellistic and Biophysical Tests

    Science.gov (United States)

    Pizzi, Rita; Wang, Rui; Rossetti, Danilo

    2016-01-01

    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. PMID:26816029

  5. 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.

  6. How good are our impressions? An audit of alginate impression quality in the production of removable prostheses.

    Science.gov (United States)

    Horwitz, Richard

    2014-05-01

    Impressions are taken regularly in practice giving vital information to the dental laboratory, but are there quality assurance systems in place to make sure that they are up to a sufficient standard? As dental professionals we have to appreciate that dental technicians can only work with the information given to them. This makes the skill of taking a good impression vital in order for us as clinicians to provide prostheses of good quality. This paper outlines an audit of alginate impressions and their quality in the making of removable prostheses. To record the quality of impression taking, and how one's own ability to critique an impression may differ from that of our colleagues.

  7. Clinical study on the success of posterior monolithic zirconia crowns and fixed dental prostheses: preliminary report

    Directory of Open Access Journals (Sweden)

    Merve Bankoğlu Güngör

    2017-09-01

    Full Text Available Objective: The purpose of this report was to present preliminary clinical results regarding the success rates and technical outcomes of posterior monolithic zirconia single tooth crowns (STs and fixed dental prostheses (FDPs. Materials and Method: Thirty-four patients received 43 posterior monolithic zirconia restorations as single tooth crowns (STs and/or fixed dental prostheses (FDPs, which were fabricated using a CAD-CAM (Computer Aided Design - Computer Aided Manufacturing system. At baseline and every 6 months, the restorations were examined for survival and technical outcomes. Success of the restorations was defined as the restoration remaining in situ, with no need for removal or replacement at follow-up visits. Technical outcomes were evaluated with a modified version of the United States Public Health Services criteria. Survival of restorations was estimated by using the Kaplan-Meier survival analysis. For each restoration, duration of follow-up was calculated from the time of placement to the date of its first failure. Results: After a mean observation period of 18.6 ± 3.9 months (between 8-24 months, cumulative survival rates were 86.7% and 92.3% for STs and FDPs, respectively. Technical evaluation revealed good marginal adaptation and crown contours; however, modifications were needed for shade and occlusion of restorations. Conclusion: These preliminary results revealed high survival rate and generally successful technical outcomes for posterior monolithic zirconia STs and FDPs.

  8. 3D surface reconstruction and FIB microscopy of worn alumina hip prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, P; Inkson, B J; Rainforth, W M [Department of Engineering Materials, Mappin St., University of Sheffield, Sheffield, S1 3JD (United Kingdom); Stewart, T [School of Mechanical Engineering, University of Leeds, Leeds, LS2 9JT (United Kingdom)], E-mail: m.rainforth@sheffield.ac.uk

    2008-08-15

    Interest in alumina-on-alumina total hip replacements (THR) continues to grow for the young and active patient due to their superior wear performance and biocompatibility compared to the alternative traditional polymer/metal prostheses. While alumina on alumina bearings offer an excellent solution, a region of high wear, known as stripe wear, is commonly observed on retrieved alumina hip components that poses concern. These in-vivo stripe wear mechanisms can be replicated in vitro by the introduction of micro-separation during the simulated walking cycle in hip joint simulation. However, the understanding of the mechanisms behind the stripe wear processes is relatively poor. 3D topographic reconstructions of titled SEM stereo pairs from different zones have been obtained to determine the local worn surface topography. Focused ion beam (FIB) microscopy was applied to examine the subsurface damage across the stripe wear. The paper presents novel images of sub-surface microcracks in alumina along with 3D reconstructions of the worn ceramic surfaces and a classification of four distinct wear zones following microseparation in hip prostheses.

  9. Implant-supported titanium prostheses following augmentation procedures: a clinical report.

    Science.gov (United States)

    Knabe, C; Hoffmeister, B

    2003-03-01

    This report describes a novel technique for fabricating retrievable implant-supported titanium (Ti) prostheses in patients requiring a comprehensive treatment plan involving the combined efforts of maxillofacial surgery and implant prosthodontics. Following bone graft reconstructive surgery and implant placement prosthetic treatment was initiated by inserting ITI-Octa abutments. An impression was made, and a framework was fabricated by fusing Ti-cast frameworks to prefabricated titanium copings by laser-welding. This was followed by veneering or fabrication of a removable denture with Ti metal re-enforcement. Favourable clinical results have been achieved using these screw-retained Ti implant-supported restorations for patients treated with reconstructive bone graft-surgery, with clinical observation periods ranging from three to four years. The present observations suggest that these screw-retained implant-supported Ti prostheses may be a meaningful contribution to implant prosthodontics, facilitating retrievable restorations of optimum biocompatibility, good marginal precision and with a good esthetic result. However, controlled clinical studies are needed to establish the long-term serviceability of these Ti restorations.

  10. Force Myography to Control Robotic Upper Extremity Prostheses: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Erina eCho

    2016-03-01

    Full Text Available Advancement in assistive technology has led to the commercial availability of multi-dexterous robotic prostheses for the upper extremity. The relatively low performance of the currently used techniques to detect the intention of the user to control such advanced robotic prostheses, however, limits their use. This article explores the use of force myography (FMG as a potential alternative to the well-established surface electro-myography (sEMG. Specifically, the use of FMG to control different grips of a commercially available robotic hand, Bebionic3, are investigated. Four male transradially amputated subjects participated in the study and a protocol was developed to assess the prediction accuracy of eleven grips. Different combinations of grips were examined ranging from six up to eleven grips. The results indicate that it is possible to classify six primary grips important in activities of daily living using FMG with an accuracy of above 70% in the residual limb. Additional strategies to increase classification accuracy, such as using the available modes on the Bebionic3, allowed results to improve up to 88.83% and 89.00% for opposed thumb and non-opposed thumb modes respectively.

  11. Creating natural-looking removable prostheses: combining art and science to imitate nature.

    Science.gov (United States)

    Patras, Michael; Kourtis, Stefanos; Sykaras, Nikitas

    2012-06-01

    Patient awareness of dental appearance has increased, resulting in more demanding esthetic requests. There is also strong evidence that increased esthetics is highly significant for complete denture acceptance and success. Taking notice of patients' perceptions of natural appearance and esthetics, the clinician can incorporate their preferences in the construction of individualized dentures that will be harmonized with their facial characteristics. Despite the evolution of materials and techniques, the vast majority of dentures still fail to look natural. Thus, producing prostheses that defy detection and successfully restore the appearance of edentulous patients remains a challenge for the clinician. This paper presents a clinical case where immediate loading of implants supporting a mandibular overdenture was combined with an opposing conventional maxillary denture to satisfy the high functional and esthetic demands of the patient. It also emphasizes the individualized esthetic performance through customization during their fabrication while taking into consideration the various clinical parameters affecting rehabilitation of the edentulous jaw. Implant-retained overdentures can significantly improve the patients' function. The esthetic performance of these restorations however, may not be satisfying the patients' expectations and demands. Customizing the artificial gingival areas and individual staining of the prefabricated acrylic teeth may improve the esthetic performance creating natural-looking removable prostheses. © 2011 Wiley Periodicals, Inc.

  12. 500 penile prostheses implanted by a surgeon in Italy in the last 30 years

    Directory of Open Access Journals (Sweden)

    Diego Pozza

    2015-09-01

    Full Text Available Objectives: The aim of our study was to report our experience with patients affected by Erectile Dysfunction (ED and undergoing penile prosthetic implantation (PPI in a single center by a single surgeon. Material and Methods: We retrospectively evaluated the clinical outcome of 500 patients (mean age: 51.5 years, range: 20-86 years affected by ED and referred to our private andrological center from January 1984 to December 2013 who underwent penile prosthesis implantation, including the reported level of patient satisfaction. Results: 182 silicone, 180 malleable, 18 monocomponent hydraulic and 120 multicomponents hydraulic prostheses were implanted by the same experienced surgeon. All patients were hospitalized for the procedure. All patients were evaluated immediately, 1 month (496 patients and, for the great majority, every year after implantation. One hundred twenty five patients were lost to follow-up. Twenty two patients underwent revision surgery for complications in the postoperative period. The most serious postoperative complications were mechanical problems (45 patients, 9.0% and infection (15 patients, 3%. Forty two (8.4% prostheses were explanted. Overall, 80% (400/500 of patients were able to have sexual intercourse and were fully satisfied with the results. Conclusions: In our experience prosthetic surgery should be considered a good solution for men affected by ED and not responsive to other therapeutic solutions. Prosthetic surgery can be performed not only in large public hospitals but also in smaller private facilities.

  13. [Failure of zirconia-based prostheses on natural teeth and implants: focus on risk factors].

    Science.gov (United States)

    Dupont, N; Koenig, V; Vanheusden, A; Mainjot, A

    2014-01-01

    Cohesive fracture of the veneering ceramic (chipping) is the first cause of failure of zirconia-based prostheses on natural teeth and implants. Besides risk factors related to the material (thermal stresses generated during the manufacturing process, framework inappropriate design), there are some clinical risk factors, which can influence the restoration prognosis. Indeed, unfavorable occlusal relationships and/or the presence of parafunctions such as bruxism and clenching, which are frequent pathologies, engender significant overloading. A retrospective study was performed at the University Hospital Center (CHU) of Liege on 147 dental and implants prostheses, placed between May 2003 and January 2012. This study highlighted a significant correlation between chipping and the absence of an occlusal nightguard (p = 0.0048), the presence of a ceramic restoration as an antagonist (p = 0.013), the presence of occlusal parafunctions (p = 0.018), and the presence of implants as support of the restorations (p = 0.026). These results underline the importance of external stress and occlusal risk factors diagnosis, as the need to perform an occlusal nightguard to patients with parafunctions.

  14. Wireless radio channel for intramuscular electrode implants in the control of upper limb prostheses.

    Science.gov (United States)

    Stango, Antonietta; Yazdandoost, Kamya Yekeh; Farina, Dario

    2015-01-01

    In the last few years the use of implanted devices has been considered also in the field of myoelectric hand prostheses. Wireless implanted EMG (Electromyogram) sensors can improve the functioning of the prosthesis, providing information without the disadvantage of the wires, and the usability by amputees. The solutions proposed in the literature are based on proprietary communication protocols between the implanted devices and the prosthesis controller, using frequency bands that are already assigned to other purposes. This study proposes the use of a standard communication protocol (IEEE 802.15.6), specific for wireless body area networks (WBANs), which assign a specific bandwidth to implanted devices. The propagation losses from in-to-on body were investigated by numerical simulation with a 3D human model and an electromagnetic solver. The channel model resulting from the study represents the first step towards the development of myoelectric prosthetic hands which are driven by signals acquired by implanted sensors. However these results can provide important information to researchers for further developments, and manufacturers, which can decrease the production costs for hand prostheses having a common standard of communication with assigned frequencies of operation.

  15. Anterior Cantilever Resin-Bonded Fixed Dental Prostheses: A Review of the Literature.

    Science.gov (United States)

    Mourshed, Bilal; Samran, Abdulaziz; Alfagih, Amal; Samran, Ahalm; Abdulrab, Saleem; Kern, Matthias

    2018-03-01

    This review evaluated the survival rate of single retainer anterior resin-bonded fixed dental prostheses (RBFDPs) to determine whether the choice of material affects their clinical outcome. An electronic search of the English peer-reviewed dental literature in PubMed was conducted to identify all publications reporting on cantilever RBFDPs until May 2016. Study information extraction and methodological quality assessments were accomplished by two reviewers independently. The searched keywords were as follows: "resin-bonded, single retainer, all-ceramic resin-bonded fixed dental prostheses (RBFDPs), all-ceramic RBFDPs, cantilever resin, RBFDPs, cantilever resin-bonded bridge, two units cantilevered, two-unit cantilevered, metal-ceramic cantilever, and metal-ceramic." Furthermore, the ''Related Articles'' feature of PubMed was used to identify further references of interest within the primary search. The bibliographies of the obtained references were used to identify pertinent secondary references. Review articles were also used to identify relevant articles. After the application of exclusion criteria, the definitive list of articles was screened to extract the qualitative data, and the results were analyzed. Overall 2588 articles were dedicated at the first review phase; however, only 311 studies were left after the elimination of duplicates and unrelated studies. Seventeen studies passed the second review phase. Five studies were excluded because they were follow-up studies of the same study cohort. Twelve studies were finally selected. The use of cantilever RBFDPs showed promising results and high survival rates. © 2016 by the American College of Prosthodontists.

  16. [Single- and multi-unit fixed dental prostheses in relation to the occlusal system].

    Science.gov (United States)

    Witter, D J; Gerritsen, A E; van Spijker, A; Creugers, N H J

    2013-02-01

    Occlusion concepts based on functional aspects offer more solid ground in the diagnostic process and in the treatment of (reduced) dentitions than morphologically and mechanically oriented occlusion concepts. Nevertheless, for occlusal reconstruction morphologically oriented guidelines are necessary. These guidelines are based on the border movements and positions of the mandible in the orofacial system, and on the location and modelling of the occlusal contacts in the occlusal system. The modelling of single- and multi-unit fixed dental prostheses must harmonize with the occlusal system. Moreover, an important feature is the relation of the anterior teeth which enables mutually protected occlusion. Characteristics of a healthy orofacial and occlusal system are: absence of pathology, perceived sufficient oral functions, variability inform and function, and adaptive capacity. When designing single- or multiunit fixed dental prostheses, a pragmatic starting point is to maintain the existing occlusion and the existing speech pattern unless arguments can be provided for alterations. The occlusal design should aim at optimizing oral functions, such as mandibular and occlusal stability.

  17. Neural prostheses in clinical applications--trends from precision mechanics towards biomedical microsystems in neurological rehabilitation.

    Science.gov (United States)

    Stieglitz, T; Schuettler, M; Koch, K P

    2004-04-01

    Neural prostheses partially restore body functions by technical nerve excitation after trauma or neurological diseases. External devices and implants have been developed since the early 1960s for many applications. Several systems have reached nowadays clinical practice: Cochlea implants help the deaf to hear, micturition is induced by bladder stimulators in paralyzed persons and deep brain stimulation helps patients with Parkinson's disease to participate in daily life again. So far, clinical neural prostheses are fabricated with means of precision mechanics. Since microsystem technology opens the opportunity to design and develop complex systems with a high number of electrodes to interface with the nervous systems, the opportunity for selective stimulation and complex implant scenarios seems to be feasible in the near future. The potentials and limitations with regard to biomedical microdevices are introduced and discussed in this paper. Target specifications are derived from existing implants and are discussed on selected applications that has been investigated in experimental research: a micromachined implant to interface a nerve stump with a sieve electrode, cuff electrodes with integrated electronics, and an epiretinal vision prosthesis.

  18. Inducing repetitive action potential firing in neurons via synthesized photoresponsive nanoscale cellular prostheses.

    Science.gov (United States)

    Lu, Siyuan; Madhukar, Anupam

    2013-02-01

    Recently we reported an analysis that examined the potential of synthesized photovoltaic functional abiotic nanosystems (PVFANs) to modulate membrane potential and activate action potential firing in neurons. Here we extend the analysis to delineate the requirements on the electronic energy levels and the attendant photophysical properties of the PVFANs to induce repetitive action potential under continuous light, a capability essential for the proposed potential application of PVFANs as retinal cellular prostheses to compensate for loss of photoreceptors. We find that repetitive action potential firing demands two basic characteristics in the electronic response of the PVFANs: an exponential dependence of the PVFAN excited state decay rate on the membrane potential and a three-state system such that, following photon absorption, the electron decay from the excited state to the ground state is via intermediate state(s) whose lifetime is comparable to the refractory time following an action potential. In this study, the potential of synthetic photovoltaic functional abiotic nanosystems (PVFANs) is examined under continuous light to modulate membrane potential and activate action potential firing in neurons with the proposed potential application of PVFANs as retinal cellular prostheses. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Math for visualization, visualizing math

    NARCIS (Netherlands)

    Wijk, van J.J.; Hart, G.; Sarhangi, R.

    2013-01-01

    I present an overview of our work in visualization, and reflect on the role of mathematics therein. First, mathematics can be used as a tool to produce visualizations, which is illustrated with examples from information visualization, flow visualization, and cartography. Second, mathematics itself

  20. 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

  1. 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

  2. Comparison of Treatment Outcomes in Partially Edentulous Patients with Implant-Supported Fixed Prostheses and Removable Partial Dentures.

    Science.gov (United States)

    Nogawa, Toshifumi; Takayama, Yoshiyuki; Ishida, Keita; Yokoyama, Atsuro

    The aim of this study was to compare masticatory performance, occlusal force, and oral health-related quality of life (OHRQoL) in patients with mandibular distal-extension edentulism between those with implant-supported fixed prostheses (ISFPs) and those with removable partial dentures (RPDs), and to evaluate relationships among them. Subjects were recruited from patients using ISFPs or RPDs for mandibular distal-extension edentulism. Masticatory performance was evaluated based on the glucose extracted from chewed gummy jelly. Occlusal force was measured with a pressure-sensitive sheet, and data were subjected to computer analysis. The Japanese version of the Oral Health Impact Profile (OHIP-J) was used to evaluate OHRQoL. The masticatory performance, occlusal force, and OHIP-J scores of the ISFP and RPD groups were compared using the Wilcoxon rank-sum test. The relationships among the variables were analyzed using the Spearman rank correlation coefficient test. Multivariate logistic regression analysis was employed with the OHIP-J score as a dependent variable. Nineteen patients with ISFPs and 25 patients with RPDs participated in this study. No significant difference was observed between the two groups with regard to masticatory performance and occlusal force. The OHIP-J score was significantly lower in the ISFP group than in the RPD group. The OHIP-J score had no significant correlation with masticatory performance, but was significantly correlated with occlusal force and the prosthetic method. Multivariate logistic regression analysis showed that younger age, RPDs, and lower occlusal force were significantly associated with a higher OHIP-J summary score. The present results suggest that the difference in masticatory performance and occlusal force between ISFPs and RPDs is small, but ISFPs are superior to RPDs with regard to OHRQoL in patients with mandibular distal-extension edentulism. In addition, there appears to be a slight correlation between the OHIP

  3. 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%

  4. 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

  5. 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.

  6. Optical devices for proximity operations study and test report. [intensifying images for visual observation during space transportation system activities

    Science.gov (United States)

    Smith, R. A.

    1979-01-01

    Operational and physical requirements were investigated for a low-light-level viewing device to be used as a window-mounted optical sight for crew use in the pointing, navigating, stationkeeping, and docking of space vehicles to support space station operations and the assembly of large structures in space. A suitable prototype, obtained from a commercial vendor, was subjected to limited tests to determine the potential effectiveness of a proximity optical device in spacecraft operations. The constructional features of the device are discussed as well as concepts for its use. Tests results show that a proximity optical device is capable of performing low-light-level viewing services and will enhance manned spacecraft operations.

  7. Design and test of a Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during training of upper limb movement.

    Science.gov (United States)

    Simonsen, Daniel; Popovic, Mirjana B; Spaich, Erika G; Andersen, Ole Kæseler

    2017-11-01

    The present paper describes the design and test of a low-cost Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during the execution of an upper limb exercise. Eleven sub-acute stroke patients with varying degrees of upper limb function were recruited. Each subject participated in a control session (repeated twice) and a feedback session (repeated twice). In each session, the subjects were presented with a rectangular pattern displayed on a vertical mounted monitor embedded in the table in front of the patient. The subjects were asked to move a marker inside the rectangular pattern by using their most affected hand. During the feedback session, the thickness of the rectangular pattern was changed according to the performance of the subject, and the color of the marker changed according to its position, thereby guiding the subject's movements. In the control session, the thickness of the rectangular pattern and the color of the marker did not change. The results showed that the movement similarity and smoothness was higher in the feedback session than in the control session while the duration of the movement was longer. The present study showed that adaptive visual feedback delivered by use of the Kinect sensor can increase the similarity and smoothness of upper limb movement in stroke patients.

  8. 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.

  9. 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)

  10. Antibacterial Efficacy of a New Gentamicin-Coating for Cementless Prostheses Compared to Gentamicin-Loaded Bone Cement

    NARCIS (Netherlands)

    Neut, Danielle; Dijkstra, Rene J. B.; Thompson, Jonathan I.; van der Mei, Henny C.; Busscher, Henk J.

    Cementless prostheses are increasingly popular but require alternative prophylactic measures than the use of antibiotic-loaded bone cements. Here, we determine the 24-h growth inhibition of gentamicin-releasing coatings from grit-blasted and porous-coated titanium alloys, and compare their

  11. Interference in adhesion of bacteria and yeasts isolated from explanted voice prostheses to silicone rubber by rhamnolipid biosurfactants

    NARCIS (Netherlands)

    Rodrigues, LR; Banat, IM; van der Mei, HC; Teixeira, JA; Oliveira, R

    Aims: 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. Methods and Results: The

  12. ENHANCED HEALING OF 30-MU-M GORE-TEX PTFE MICROARTERIAL PROSTHESES BY ALCOHOL-PRETREATMENT

    NARCIS (Netherlands)

    VANDERLEI, B; STRONCK, JW; WILDEVUUR, CRH

    1991-01-01

    Polytetrafluoroethylene (PTFE) microvascular prostheses with a fibril length of 30-mu-m were pretreated with alcohol (n = 18), implanted into the abdominal aorta of rats and were evaluated at 1 day (n = 3), 1 week (n = 3), 3 weeks (n = 6) and 6 weeks (n = 6) to determine whether alcohol-pretreatment

  13. Sport prostheses and prosthetic adaptations for the upper and lower limb amputees : an overview of peer reviewed literature

    NARCIS (Netherlands)

    Bragaru, Mihai; Dekker, Rienk; Geertzen, Jan H. B.

    Background: Sport prostheses are used by both upper- and lower-limb amputees while participating in sports and other physical activities. Although the number of these devices has increased over the past decade, no overview of the peer reviewed literature describing them has been published

  14. 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.

  15. The influence of age, sex, bulb position, visual feedback, and the order of testing on maximum anterior and posterior tongue strength and endurance in healthy belgian adults.

    Science.gov (United States)

    Vanderwegen, Jan; Guns, Cindy; Van Nuffelen, Gwen; Elen, Rik; De Bodt, Marc

    2013-06-01

    This study collected data on the maximum anterior and posterior tongue strength and endurance in 420 healthy Belgians across the adult life span to explore the influence of age, sex, bulb position, visual feedback, and order of testing. Measures were obtained using the Iowa Oral Performance Instrument (IOPI). Older participants (more than 70 years old) demonstrated significantly lower strength than younger persons at the anterior and the posterior tongue. Endurance remains stable throughout the major part of life. Gender influence remains significant but minor throughout life, with males showing higher pressures and longer endurance. The anterior part of the tongue has both higher strength and longer endurance than the posterior part. Mean maximum tongue pressures in this European population seem to be lower than American values and are closer to Asian results. The normative data can be used for objective assessment of tongue weakness and subsequent therapy planning of dysphagic patients.

  16. 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.

  17. 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.

  18. Traditional test administration and proactive interference undermine visual-spatial working memory performance in schizophrenia-spectrum disorders.

    Science.gov (United States)

    Girard, Todd A; Wilkins, Leanne K; Lyons, Kathleen M; Yang, Lixia; Christensen, Bruce K

    2018-05-31

    Introduction Working-memory (WM) is a core cognitive deficit among individuals with Schizophrenia Spectrum Disorders (SSD). However, the underlying cognitive mechanisms of this deficit are less known. This study applies a modified version of the Corsi Block Test to investigate the role of proactive interference in visuospatial WM (VSWM) impairment in SSD. Methods Healthy and SSD participants completed a modified version of the Corsi Block Test involving both high (typical ascending set size from 4 to 7 items) and low (descending set size from 7 to 4 items) proactive interference conditions. Results The results confirmed that the SSD group performed worse overall relative to a healthy comparison group. More importantly, the SSD group demonstrated greater VSWM scores under low (Descending) versus high (Ascending) proactive interference; this pattern is opposite to that of healthy participants. Conclusions This differential pattern of performance supports that proactive interference associated with the traditional administration format contributes to VSWM impairment in SSD. Further research investigating associated neurocognitive mechanisms and the contribution of proactive interference across other domains of cognition in SSD is warranted.

  19. Tribology and wear of metal-on-metal hip prostheses: influence of cup angle and head position.

    Science.gov (United States)

    Williams, Sophie; Leslie, Ian; Isaac, Graham; Jin, Zhongmin; Ingham, Eileen; Fisher, John

    2008-08-01

    Clinical studies have indicated that the angular position of the acetabular cup may influence wear in metal-on-metal total hip bearings. A high cup angle in comparison to the anatomical position may lead to the head being constrained by the superior lateral surface and rim of the cup, thus potentially changing the location of the contact zone between the head and the cup. The aim of this study was to test the hypothesis that both a steep cup angle and a lateralized position of the head can increase head contact on the superior rim of the cup, with the consequence of increased wear. Hip-joint simulator studies of metal-on-metal bearings were undertaken with cup angles of 45 degrees and 55 degrees . The femoral head was either aligned to the center of the cup or placed in a position of microlateralization. Wear was measured gravimetrically over 5 million cycles. A steep cup angle of 55 degrees showed significantly higher long-term steady-state wear than a standard cup angle of 45 degrees (p < 0.01). The difference was fivefold. Microlateralization of the head resulted in a fivefold increase in steady-state wear compared with a centralized head. The combination of a steep cup angle and a microlateralized head increased the steady-state wear rate by tenfold compared with a standard cup angle with a centralized head. These studies support the hypothesis that both an increased cup angle and a lateral head position increase wear in metal-on-metal hip prostheses.

  20. Biotribological behavior of Ag-ZrCxN1-x coatings against UHMWPE for joint prostheses devices.

    Science.gov (United States)

    Calderon V, S; Sánchez-López, J C; Cavaleiro, A; Carvalho, S

    2015-01-01

    This study aims to evaluate the structural, mechanical and tribological properties of zirconium carbonitrides (ZrCxN1-x) coatings with embedded silver nanoparticles, produced with the intention of achieving a material with enhanced multi-functional properties, including mechanical strength, corrosion resistance, tribological performance and antibacterial behavior suitable for their use in joint prostheses. The coatings were deposited by direct current (DC) reactive magnetron sputtering onto 316 L stainless steel, changing the silver content from 0 to 20 at% by modifying the current density applied to the targets. Different nitrogen and acetylene gas fluxes were used as reactive gases. The coatings revealed different mixtures of crystalline ZrCxN1-x, silver nanoparticles and amorphous carbon phases. The hardness of the films was found to be mainly controlled by the ratio between the hard (ZrCxN1-x) and soft (Ag and amorphous carbon) phases in the films, fluctuating between 7.4 and 20.4 GPa. The coefficient of friction, measured against ultra-high molecular weight polyethylene (UHMWPE) in Hank's balanced salt solution with 10 gL(-1) albumin, is governed by the surface roughness and hardness. The UHMWPE wear rates were in the same order of magnitude (between 1.4 and 2.0 × 10(-6)mm(3)N(-1)m(-1)), justified by the effect of the protective layer of albumin formed during the tests. The small differences were due to the hydrophobic/hydrophilic character of the surface, as well as to the silver content. Copyright © 2014 Elsevier Ltd. All rights reserved.