1,720,977 research outputs found
Patient Alert (TM) to detect ICD lead failure: efficacy, limitations, and implications for future algorithms
No full textAims An algorithm that alerts implantable cardioverter-defibrillator (ICD) patients, in case of abnormal lead impedance (Patient Alert (TM), Medtronic), may help to recognize lead dysfunction. We aimed to determine the utility of Patient Alert for ICD lead-failure detection in a prospective study. Methods and results Three hundred and sixty ICD patients were followed for 22 +/- 14 months. Patient Alert was active for pacing impedance 2000-3000 Omega, and high-voltage conductor impedance 200 fl. Ten alert events and a total of 29 severe system complications occurred. Patient Alert detected three of 10 ICD lead failures, with a positive predictive value (PPV) of 77.8% for any severe system complication. Retrospective analysis identified 23 patients with a sensing integrity counter (SIC) > 300 and revealed an additional four prior undetected lead defects. SIC detected ICD lead failure with 92.9% sensitivity and a PPV of 59.1%. Eight of nine patients with a false-positive SIC had an integrated bipolar lead. Patient Alert combined with SIC detected all ICD lead failures and 71.4% of all severe lead complications. Conclusions Patient Alert, based on daily lead-impedance measurement, detected one-third of all ICD lead failures. Combined use with continuous lead integrity monitoring (SIC) increased sensitivity to 100%. Integrated bipolar leads may yield a false-positive SIC. Incorporating SIC and automated pace/sense threshold measurement may improve Patient Alert sensitivity for severe lead complications
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Evaluation of fusion beat detection with a new ventricular automatic capture algorithm in ICDs.
No full textThis study evaluated a newly developed automatic capture verification scheme for
implantable cardioverter defibrillators (ICDs) regarding discrimination of
capture, fusion, and noncapture beats, with an emphasis on fusion detection. The
algorithm uses evoked response detection based on a sensing vector from right
ventricular shocking coil to Can. Patients undergoing ICD implant or replacement
were enrolled in this study. An external system was used for pacing and data
acquisition. To provoke ventricular fusion beats, VVI patients were paced close
to the rate of their intrinsic rhythm and DDD patients were paced close at their
intrinsic PR interval. Surface ECG and wideband filtered intracardiac
electrograms were recorded for off-line analysis. Each paced beat was
independently classified visually by surface ECG and by the automatic detection
algorithm. The algorithm performance was then evaluated by comparing the
classification results. Twenty-seven patients (22 males, 5 females; 63.8 +/-
12.5 years) were analyzed. Device and lead demographics were: 18 DDD/9 VVI; 16
dedicated bipolar, 11 integrated bipolar leads; 18 acute, 9 chronic (3.7 +/- 2.0
years) leads. In total, 2064 beats were analyzed, including 1,477 fusion beats
and 587 capture beats. Fusion detection sensitivity and specificity were 99.5%
and 99.0%, respectively. Seven true-fusion beats (0.5%) were classified as
capture and 6 capture beats (1.0%) were identified as fusions. Capture or fusion
beats were never detected as non-capture beats. It is concluded that the
algorithm was effective in detecting fusion beats. It could potentially be used
in ICD applications that need accurate fusion detection
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