83 research outputs found
Matemathical models in bioengineering
No full textWe intend here to offer an overview of how biology and medicine entered into a process of mathematization, starting with Leonardo until reaching our current days, pointing out some outstanding areas without forgetting essential concepts that remain as theoretical columns or pillars.Fil: Valentinuzzi, Maximo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Arini, Pedro David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentin
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
Horses also deserve our respect and love
No full textAnimals, no doubt, trigger our emotions and have contributed to medical knowledge and human life.1, 2 In many respects, the horse is very peculiar. It never occurred to me the feelings and communication that can be established with it. It is extremely sensitive and clever, showing a tremendous learning capacity, especially when properly treated and taken care of...Fil: Valentinuzzi, Maximo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentin
THE TIMEKEEPING SYSTEM: A KEY ORGANIZATIONAL ELEMENT
No full textLife has evolved in a cyclic environment, and consequently, during evolution the time dimension was incorporated in the inner organization of every single biological structure. This incorporation is evident in the biological rhythms detected in the whole phylogenetic range, from unicellular organisms to humans, and at all organizational level within an organism, from molecular to behavioral variables. ?Doing the right thing at the right time? enhances reproduction, health, survival and longevity. Biological clocks generate such rhythms, afferent pathways synchronize them with the cyclic environment, and efferent pathways convey this time information to the organism as a whole. In mammals, the main biological clocks are localized in the hypothalamus, the suprachiasmatic nuclei, which receive direct specialized inputs from the retinas allowing synchronization to the external night-day maintaining the organism in tune with its environment. A particular and refined set of photoreceptors allows this light perception. A network of peripheral clocks in other neural, as well as non-neural tissues throughout the organism, receives this time information assuring precise temporal relationship between every system within the organism, the so-called internal temporal order. When considering any biological system, time of sampling should always be tracked, and the use of basic and simple chronobiological methods considered so avoiding misinterpretations.Fil: Valentinuzzi, Verónica Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Oda, Gisele Akemi. Universidade de Sao Paulo. Departamento de Fisiología. Instituto de Biociencias; Brasi
Physical Rehabilitation: A Historical Look
No full textMedicine aims toward restoring, maintaining, and improving human health, and engineering aims toward restoring, maintaining and improving human wellness. Both disciplines apply knowledge from science and technology at large to accomplish such objectives. Bioengineering, also called biomedical engineering, is defined as the application of engineering principles and techniques to problems in medicine and biology (always with restoration, maintenance, and improvement in mind), which now also includes veterinary medicine, and the environment in general.Fil: Valentinuzzi, Maximo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: López Celani, Natalia Martina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Departamento de Electrónica y Automática. Gabinete de Tecnología Médica; Argentin
Ludwig: The physiologist
No full textThe thought reproduced in the above epigraph is taken from an article by Thurau et al. [1], who attribute it to Arthur Schopenhauer (17881860), an outstanding philosopher and author of the far-reaching piece Die Welt als Wille und Vorstellung (The World as Will and Representation). In German, it would perhaps read as etwas denken, das niemand vorher gedacht hat, während etwas sehen, was jeder sieht. We could not assert whether Schopenhauer really said that, but it should not be at all surprising if it were, because it sounds simple, perhaps even naïve, and very deep, indeed. It fits perfectly to Carl Friedrich Wilhelm Ludwigs personality (18161895), whom we will look at as physiologist in this second note. Yes, second notebecause in the first one [2], we looked at him as bioengineer. A third and last Retrospectroscope column completing this series will deal with his wonderful and always humble and generous activities as teacher. © 2012 IEEE.Fil: Valentinuzzi, Maximo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Beneke, Klaus. Christin-Albrechts-University; 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
Ludwig: The Bioengineer
No full textOn the basis of the strict exclusion of the vis vitalis, the demand was raised by Carl Ludwig, Helmholtz, Du Bois-Reymond, and Brucke for a physiology which was causal-analytical and physically and chemically experimental. If, out of these four investigators, we pick Ludwig as the actual founder of modern physiology, the grounds for this must be justified specifically. That modern physiology is not to be contemplated without the works of the three great students of Johannes Muller is explicitly emphasized. However, Carl Ludwig occupies a special position for physiology [1]. © 2012, IEEE. All rights reserved.Fil: Valentinuzzi, Maximo. 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; ArgentinaFil: Beneke, Klaus. Universitat Erlangen-nurmberg. Institute Of Inorganic Chemistry; 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
The brain willis circle and ring electric power systems analogies
No full textBlood flowing to the brain keeps it alive, while electrons flowing to inhabited civilized places keep them active, leading to greater understanding of the world. What, however, of those many human beings still confined to distant hostile regions, unaware of the magic of electricity now over a century old. The word analogy is a synonym of likeness, resemblance, similitude, or affinity and involves two concepts being placed side by side, as in a comparison. The workings of nature and those of human societies are amenable to such analogous comparison?even though the evolution of the natural world obviously spans millions of years, while human societies are much younger, relatively puppies by comparison. This article considers two interesting examples from these two realms that show remarkable similarities (possibly a result of sheer chance), i.e., a circulatory brain anastomosis, the circle of Willis (CW), and modern power transmission-distribution systems in the ring arrangement. Remember that electric networks handle the flow of charges [say, in coulombs per second (C/s) or electric charge per unit time, which is current), whereas hydraulic systems deal with fluid flow [say, in liters per minutes (L/min) or volume/unit time or fluid mass/unit time]. Hence, these systems too are analogous, a well-known fact often mentioned by instructors of electrical engineering courses. Cerebral circulation refers to the movement of blood through the network of blood vessels supplying the brain, the primary governing organ that makes us human beings. The rate of cerebral blood flow in adults is typically 750 mm/min, representing about 15% of cardiac output. The brain is very vulnerable to compromises in its blood supply; consequently, its circulatory system has many safeguards, of which the CW is one. Brain circulatory failure results in cerebrovascular accidents, commonly known as strokes, a health situation of considerable concern.Fil: Valentinuzzi, Maximo. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: Diaz, Ricardo Ruben. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; Argentin
Autism: Historic View and a Current Biomedical Engineering Approach [Retrospectroscope]
No full textThis paper presents a software specially designed for children with autism spectrum disorder (ASD) and its evaluation with a selected group of patients. The software is simple, easy to manage, and with a friendly interface; it has activities that stimulate the cognitive and motor development. The Fitt´s law and the Scale Usability System were used to evaluate the performance of the software, carried out with a group of children suffering ASD that attend phonoaudiology therapies at the state hospital. The results are very encouraging because the children were interested using the software and also the evaluation tests allow the quantification of the performance, showing better coefficients with the SicaaKids environment than with the Windows® desktop.Fil: Pérez Berenguer, María Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Departamento de Electrónica y Automática. Gabinete de Tecnología Médica; ArgentinaFil: Ponce, Sergio Damián. Universidad Tecnológica Nacional; ArgentinaFil: Piccinini, David J.. Universidad Tecnológica Nacional; ArgentinaFil: Lopez, Natalia. Universidad Nacional de San Juan. Facultad de Ingeniería. Departamento de Electrónica y Automática. Gabinete de Tecnología Médica; ArgentinaFil: Valentinuzzi, Maximo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán; Argentin
Arm EMG during abduction and adduction: Hysteresis cycle
No full textThe electromyographic study of the muscles involved in the complex movements of the shoulder, is usually one way to quantifying the static and dynamic joint's behavior. In particular, the deltoid medium EMG produced a phenomenon similar to a hysteresis cycle when its amplitude was plotted as a function of the lateral angular position during a static, step by step, sequential abduction-adduction of the arm. Such a cycle was consistently repeated in 16 subjects (12 males and 4 females). The paired Student t-test, after comparing the mean EMG values of the rectified wave for the same arm opening angle between abduction and adduction, produced a highly significant difference (α<0.001) in all subjects. In all likelihood, it manifests the participation of muscles other than the deltoid medium in the overall movement (as for example, the anterior and posterior deltoids), that is, they are collaborating muscles that are different in the opening or lifting of the arm from those involved in its closure or lowering. Thus, it is concluded that a quantifiable and significant deltoid medium EMG difference has been demonstrated when the muscle is either ready to abduction or ready to adduction. The effect is fully reproducible between 0 and 90 degrees of an arm in static position within the scapular plane.Fil: Politti, Julio César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería; ArgentinaFil: Felice, Carmelo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería; ArgentinaFil: Valentinuzzi, Maximo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Bioingeniería; Argentin
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