8,743 research outputs found
VENTRICULAR FIBRILLATION DETECTION
No full textIn automatic defibrillation, early detection of the arrhythmia constitutes an essential and extremely sensitive task. Its failure means no shock delivery and, hence, no possible reversal leading to the patient’s death. Besides, as Golden Rule, a shock should not be delivered to a collapsed patient not in cardiac arrest and a successfully defibrillated patient should not be defibrillated again. After defining basic evaluating parameters (sensitivity, specificity, receiver operating curve, positive predictivity and accuracy), several algorithms are reviewed comparing them at the end of the chapter in an attempt to help the designer engineer is his/her selection. Acronyms are used along the text for the sake of space knowing the risk of confusion, although frequently their full identification is repeated and realizing that occasionally the same algorithm shares two abbreviations. To make navigation in this chapter easier, find here listed the seven algorithms treated plus other nine mentioned in the discussion, including also two algorithms for QRS complex detection, and calling attention to some overlapping between the two sets, that is: Probability Density Function (PDF), Threshold Crossing Intervals (TCI), Cardiac Frequency (CF), Signal Morphology (SM) or Correlation Waveform Analysis (CWA), Time-Frequency Analysis (TFA), Wavelet Transform (WT), Phase Space Analysis (PSA), in the first group, followed by Threshold Crossing Intervals (TCI), described in section 4.2.2, AutoCorrelation Fischer (ACF95) algorithm, based on Correlation Waveform Analysis (CWA), explained in section 4.2.4, VF Filter algorithm, after Kuo and Dillman (1978); Spectral (SPEC) algorithm based on Fourier Transform analysis, described in section 4.2.5, Complexity (CPLX) algorithm, the Standard Exponential (STE) algorithm, the Modified Exponential Algorithm (MEA), an STE akin, the Signal Comparison Algorithm (SCA), the Wavelet (WVL) Algorithm, also explained in section 4.2.6. Likewise, two QRS complexes detection algorithms are considered: Tompkins (TOMP, see section 4.2.3), and LI algorithm, (see section 4.2.6).Fil: Laciar Leber, Eric. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Valentinuzzi, Maximo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; Argentina. Universidad Nacional de Tucumán; Argentin
Scientific Discoveries and Technological Inventions: Their Relativistic History Effect
No full textTime … how elusive and slithering, almost feared by the human being, for it disappears through the fingers as when trying to hold water and sand on a beachFil: Arini, Pedro David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática; ArgentinaFil: Bianchi, Jorge.Fil: Valentinuzzi, Max E.
Intracardiac Pressure - Volume Diagrams and Their Links with Thermodynamics
No full textThe main objective of this column is to historically connect the pressure–volume diagram (PVD) of the heat mechanical engines and that of the heart—a natural chemical engine—both types being generators of useful work.Fil: Valentinuzzi, Max E.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Bonomini, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ingenieria. Instituto de Ingeniería Biomédica; ArgentinaFil: Arini, Pedro David. Universidad de Buenos Aires. Facultad de Ingenieria. Instituto de Ingeniería Biomédica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Enseñanza de la escritura de Max Aub: comprensión y memoria
No full textEste texto analiza a obra testimonial de Max Aub sobre su experiencia en los campos de concentración en Francia desde una perspectiva de discursos comparados. Para destacar las estrategias de la escritura del autor recuperables por otros proyectos discursivos que persigan la sensibilización y la denuncia a través del cruce entre la comunicación y la éticaThis text analyses the testimonial work of Max Aub about his experience in the French concentration camps in France from comparative discourses approach. It emphasizes the writing strategies used by the author useful for other awareness and denounce discourses through the dialogue among communication and ethic
Max Brooks literary reading flier
No full text2012 Bismarck State College Visiting Writers Series and ArtsQuest present: Max Brooks. April 25, 7:30 p.m.; Belle Mehus Auditorium. Max Brooks is the author of World War Z: An Oral History of the Zombie War and the graphic novel The Zombie Survival Guide: Recorded Attacks
Max Frisch's novel: Stiller. A study
No full text The attempt is made in the following study to present an interpretation of the novel "Stiller" by the Swiss author, Max Frisch, by tracing through the novel the dominant themes of the graven-image or 'Bildnis' and that of the problem of freedom with reference to the novel's main character. ThesisMaster of Arts (MA
A Transfer Report on the Development of a Framework to Evaluate Search Interfaces for their Support of Different User Types and Search Tactics
No full textAs the understanding of search systems, user needs and seeking strategies is developing, the design of search user interfaces is evolving to support more complicated and exploratory forms of search. With the design of new search features that enable these richer modes of exploration, comes the need to better understand the support they provide. In this report a new evaluation framework is presented that analyses search features for how they a) contribute to an overall interface, b) allow users to carry out different search tactics, and c) support different types of users and their needs. The novel contributions of the framework improve on some of the limitations of typical user studies, and allow search systems to be systematically analysed in much more detail and in much less time. The presented evaluation framework is then validated in three ways. First the validity of the models used as the building blocks of the framework are investigated through related work. Second the method of integrating these building-block models is validated and strengthened by consensus of expert opinion. Third, the overall approach is validated by comparing its analyses to the results of previously carried out user studies. The validation process has shown both the value of the framework and identified areas of future work that should be addressed for the framework to be completed. This report concludes with the set of contributions that the framework makes, and why the remaining work will be challenging, but critical to the final design
Ludwig: The Teacher
No full textThis is the third and last article of a series devoted to Carl Friedrich Wilhelm Ludwig's outstanding life (29 December 1816–23 April 1895). The first article portrayed him as a bioengineer [1] and the second as a physiologist [2]. Here, we view him as a teacher, the teacher par excellence, as recognized and commended by Theodor Beer (1866–1919)—a naturalist and physiologist who, incidentally, had a disgraced, sad, and ruined life [3]—making it a dramatic history subject, especially for its several human facets and controversial feelings and beliefs. In his own words: Ludwig war der deutsche Professor par excellence, der deutsche Professor im besten Sinne des Wortes, er war nicht nur tüchtig, sondern auch bedeutend, ein Klassiker in seiner Art.Fil: Valentinuzzi, Max E.. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Beneke, Klaus. Christian-AlbrechtsUniversity; AlemaniaFil: González, Germán Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentin
Prediction of ventricular fibrillation based on the ST-segment deviation: Allometric model
No full textBased on some reported clinical data, we attempt to apply the allometric law for evaluating the probability of ventricular fibrillation when electrocardiographic ST-segment deviations are determined. The deviation is measured in millimeters at the standard calibration of 1mV = 10mm and the probability in percent. Using the equation VF P = δ + β (ST) in log-log representation, the fitting procedure produced the following overall coefficients: Average β = 1.11, with a maximum = 1.65 and a minimum = 0.78; Average δ = 0.83, with a maximum = 1.39 and a minimum = 0.41. For a 2mm ST-deviation, the full range of predicted ventricular fibrillation probability extended from about 6% at 1 month up to 47% at 4 years after the original cardiac event. These results, at least preliminarily, appear acceptable and still call for full clinical test. The model seems promising if other parameters were taken into account, such as cardiac enzyme concentration, ischemic or infarcted epicardial areas or ejection fraction. It is concluded, considering these results and a few references found in the literature, that the allometric model shows promising features in cardiology.Fil: Arini, Pedro David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentina. Universidad de Buenos Aires. Instituto de Ingeniería Biomédica; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Bonomini, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentina. Universidad Maimónides; ArgentinaFil: Valentinuzzi, Max E.. Universidad de Buenos Aires. Instituto de Ingeniería Biomédica; Argentina32nd Annual International Conference of the IEEE EMBSArgentinaEl Instituto de Ingenieros Eléctricos y Electrónico
Laplace's law: Its epistemological context
No full textIn the two preceding notes about Laplace's law, we first recalled what it is and how it is frequently mentioned or applied in physiology, finding that in this particular case, there is an apparent separation between physiology and physics supposedly backing up the subject. Moreover, mistakes are almost a rule while amazingly and fortunately, the overall practical conclusions after very heavy simplifications are correct and well demonstrated by actual experiments and postmortem studies. The second note dealt with the mathematics of the law, and we believe that we practically exhausted all the pathways leading to the final formula, both when the wall thickness is negligible and when it is finite and significant. Now, our hat displays the epistemologist's sign, upsetting perhaps some readers, but without totally leaving out the quantitative view. Hence, the objectives of the note are established as follows: T general objective: To introduce, discuss, and eventually produce answers for the epistemological aspects associated with Laplace's law specific objective: To discern if a mathematical equation has the same reach when obtained from two different physical settings (in our case, a phenomenon found in capillaries and the behavior of hollow stretchable cavities).Fil: Valentinuzzi, Max E.. Universidad de Buenos Aires. Facultad de Ingenieria. Instituto de Ingeniería Biomédica; ArgentinaFil: Kohen, Alberto J.. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Zanutto, Bonifacio Silvano. Universidad de Buenos Aires. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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