1,720,968 research outputs found
SAR evaluation of wireless antenna on implanted cardiac pacemaker
Full text linkFor many people, a pacemaker represents something scary because it is related to heart disease. However, that is not the main purpose of this paper, the object of the article is the technical aspect of pacemakers, in particular, their calculation of specific absorption rate values, to which the pacemaker is exposed. A pacemaker generates electrical discharges that are transferred into the heart via a lead wire and electrodes. Authors focus on the impact of Wi-Fi signal antennas on a pacemaker. A dipole antenna working in the frequency range around 5 GHz is chosen as a source of electromagnetic radiation because this kind of antennas is relatively new and it is not widely used yet. Nevertheless, it represents a potential for the future. The experiment is performed through electromagnetic simulation software called CST Microwave Studio that provides tools for SAR calculation and it allows to visualise the scatter of the resulting SAR values around the pacemaker or human torso. © 2017 Informa UK Limited, trading as Taylor & Francis Group.CZ.1.05/2.1.00/03.0089, ERDF, European Regional Development FundInternal Grant Agency of Tomas Bata University [IGA/CebiaTech/2016/005]; Ministry of Education, Youth and Sports of the Czech Republic [LO1303 (MSMT-7778/2014)]; European Regional Development Fund [CZ.1.05/2.1.00/03.0089
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
EMC Analysis of the Pacing Activity of an Implantable Cardiac Medical Device
No full textThis paper presents an extensive EMC analysis of the pacing activity of an Implantable Cardiac Medical Device (ICMD), namely an Implantable Cardioverter Defibrillator (ICD). The proposed procedure (Pacing Counter, PC) consists of monitoring the pacing activity of the ICD under test continuously, by counting the number of pacing events occurring over a given time horizon. As a result, their variations allow the identification of the inhibition process of the device under test. The PC has been carried out with and without electromagnetic noise in order to verify how ICD inhibition process is affected by electromagnetic noise. The experiments have been carried out in accordance with international standards and within an anechoic chamber, which guarantees also an appropriate shielding against external electromagnetic noise
EMC assessment of a switching mode power supply for electromedical devices
No full textThis paper presents the design and electromagnetic characterization of a Switching Mode Power Supply (SMPS) for an impedance cardiometry (ICARD). The proposed SMPS consists of a flyback converter, which best match the several application requirements (galvanic isolation, compactness, multi-output and/or multi-input, simple construction, etc.). Two different flyback prototypes have been thus designed and manufactured, which resort to silicon-based and Silicon Carbide (SiC) devices respectively. Several tests have been then carried out in order to assess EMC performances of both the prototypes for comparison purposes. The results have shown superior performances of the SiC-based prototype, which is thus chosen as the best solution for the SMPS. In conclusion, several EMC tests on the final SMPS prototype are presented and discussed
Procedimento per la Verifica del Corretto Funzionamento di un Dispositivo Cardiaco Impiantabile
No full textProcedimento per la verifica del corretto funzionamento di un dispositivo cardiaco impiantabile (ICMD) comprendente le fasi di:
a) determinare una soglia di sensibilità positiva (σ+) di detto dispositivo cardiaco impiantabile (ICMD);
b) decrementare il valore di detta ampiezza di un valore predefinito (Δa);
c) verificare se il dispositivo ICMD è effettivamente in una fase di pacing rilevando una frequenza di stimolazione acquisita (facq) corrispondente ad una predefinita frequenza mode switch (fMS) del dispositivo cardiaco (ICMD);
d) in caso positivo, definire tale valore di ampiezza come soglia di continuità positiva (σc+);
e) in caso negativo, ripetere i passi b)-d)
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Oversensing and Undersensing of Implantable Cardiac Medical Devices Exposed to EMI
No full textOversensing and undersensing issues of Implantable Cardiac Medical Devices (ICMDs) are addressed in this paper. Particularly, an extensive experimental study has been performed in order to highlight that EMI affects ICMD sensing performances in correspondence of specific heartbeat status in terms of both frequency and amplitude. Experiments have been carried out on both a Pacemaker and an Implantable Cardioverter Defibrillator within an anechoic chamber. This guarantees a proper EMI injection, whose frequency has been chosen in accordance with ANSI / AAMI ISO 14117: standard 2012. In addition, such an environment also guarantees and appropriate shielding against external EMI sources, thus ensuring the reliability of the tests
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