Técnicas de Adquisición y Procesamiento de Señales Electrocardiográficas en la Detección de Arritmias Cardíacas

The development of ambulatory monitoring systems and its electrocardiographic (ECG) signal processing techniques has become an important field of investigation, due to its relevance in the early detection of cardiovascular diseases such as the arrhythmias. The current trend of this technology is oriented to the use of portable equipment and mobile devices such as Smartphones, which have been widely accepted due to the technical characteristics and common integration in daily life. A fundamental characteristic of these systems is their ability to reduce the most common types of noise by means of digital signal processing techniques.  Among the most used techniques are the adaptive filters and the Discrete Wavelet Transform (DWT) which have been successfully implemented in several studies. There are systems that integrate classification stages based on artificial intelligence, which increases the performance in the process of arrhythmias detection. These techniques are not only evaluated for their functionality but for their computational cost, since they will be used in real-time applications, and implemented in embedded systems. This paper shows a review of each of the stages in the construction of a standard ambulatory monitoring system, for the contextualization of the reader in this type of technology.El desarrollo de sistemas de  monitoreo  ambulatorio  y  sus  técnicas  de  procesamiento  de  la  señal  electrocardiográfica (ECG) se han convertido en un importante campo de investigación, debido a su relevancia en la detección temprana de enfermedades cardiovasculares, tales como arritmias. La tendencia actual de esta tecnología está orientada al uso de equipos portátiles y dispositivos móviles como los Smartphones, que han sido ampliamente aceptados debido a sus características técnicas y a su integración, cada vez más común, en la vida diaria. Una característica fundamental de estos sistemas es su capacidad de reducir los tipos más comunes de ruido mediante técnicas de procesamiento de señales digitales. Entre las técnicas más utilizadas se encuentran los filtros adaptativos y la Transformada Discreta Wavelet (DWT, por sus siglas en inglés), los cuales han sido implementados exitosamente en diversos estudios. Así mismo, se reportan sistemas que integran etapas de clasificación basadas en inteligencia artificial, con lo cual se aumenta el rendimiento en el proceso de detección de arritmias. En este sentido, estas técnicas no solo son evaluadas por su funcionalidad, sino por su costo computacional, debido a que deben ser utilizadas en aplicaciones en tiempo real, e implementadas en sistemas embebidos. Este documento presenta una revisión del estado del arte de cada una de las etapas en la construcción de un sistema de monitoreo ambulatorio estándar, para la contextualización del lector en este tipo de tecnologías

Ecos de la academia: Revista de la Facultad de Educación, Ciencia y Tecnología - FECYT Nro 2

Ecos de la academia, Revista de la Facultad de Educación Ciencia y Tecnología es una publicación científica de la Universidad Técnica del Norte, con revisión por pares a doble ciego que publica artículos en idioma español, quichua, portugués e inglés. Se edita con una frecuencia semestral con dos números por año.En ella se divulgan trabajos originales e inéditos generados por los investigadores, docentes y estudiantes de la FECYT, y contribuciones de profesionales de instituciones docentes e investigativas dentro y fuera del país, con calidad, originalidad y relevancia en las áreas de ciencias sociales y tecnología aplicada.Relación Universidad-Sociedad en la Universidad Técnica del Norte. Estudio crítico. Seducción y erotismo en la publicidad. Estudio para la implementación de vehículos eléctricos en la ciudad de Ibarra. Determinación del perfil antropométrico en escolares del Colegio Universitario UTN de Ibarra. Una maldad desapasionada. Reflexiones etnográficas sobre dos requerimientos de las prácticas violentas en sociedades modernas: distancia y legitimación. Sociabilidad y movimientos sociales en la crisis (sistémica) capitalista. Procesos lingüísticos y factores que influyen en la adquisición del idioma inglés. “Castillos en la costa”: una pintura del paisajista romántico español Genaro Pérez Villamil en el Museo Nacional de Bellas Artes de La Habana. Gestión y visibilidad de las publicaciones científicas en Ecuador. La ética en la inclusión de estudiantes con capacidades diferentes en la educación superior en Ecuador. La Universidad latinoamericana y su vinculación a la sociedad. Tisuacryl, estudio de caso sobre la innovación. Implementación del equipo de intervención psicosocial de emergencia en el Cuerpo de Bomberos de Ibarra. La opinión pública y la Televisión Universitaria-UTN. Momento político de la campaña electoral. Líneas de investigación: importancia para las instituciones de educación superior. El desarrollo de la crítica responsable en el estudiante universitario como parte de su formación ciudadana. Fábrica Imbabura. Ayer y hoy en imágenes. Patrimonio de la arquitectura religiosa de Ibarra. Un estudio histórico-artístico. Georreferenciación y reconocimiento de los sitios arqueológicos del Cantón Ibarra

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Identification and reconstruction of low-energy electrons in the ProtoDUNE-SP detector

Measurements of electrons from $\nu_e$ interactions are crucial for the Deep Underground Neutrino Experiment (DUNE) neutrino oscillation program, as well as searches for physics beyond the standard model, supernova neutrino detection, and solar neutrino measurements. This article describes the selection and reconstruction of low-energy (Michel) electrons in the ProtoDUNE-SP detector. ProtoDUNE-SP is one of the prototypes for the DUNE far detector, built and operated at CERN as a charged particle test beam experiment. A sample of low-energy electrons produced by the decay of cosmic muons is selected with a purity of 95%. This sample is used to calibrate the low-energy electron energy scale with two techniques. An electron energy calibration based on a cosmic ray muon sample uses calibration constants derived from measured and simulated cosmic ray muon events. Another calibration technique makes use of the theoretically well-understood Michel electron energy spectrum to convert reconstructed charge to electron energy. In addition, the effects of detector response to low-energy electron energy scale and its resolution including readout electronics threshold effects are quantified. Finally, the relation between the theoretical and reconstructed low-energy electron energy spectrum is derived and the energy resolution is characterized. The low-energy electron selection presented here accounts for about 75% of the total electron deposited energy. After the addition of lost energy using a Monte Carlo simulation, the energy resolution improves from about 40% to 25% at 50~MeV. These results are used to validate the expected capabilities of the DUNE far detector to reconstruct low-energy electrons.Comment: 19 pages, 10 figure

Impact of cross-section uncertainties on supernova neutrino spectral parameter fitting in the Deep Underground Neutrino Experiment

A primary goal of the upcoming Deep Underground Neutrino Experiment (DUNE) is to measure the $\mathcal{O}(10)$ MeV neutrinos produced by a Galactic core-collapse supernova if one should occur during the lifetime of the experiment. The liquid-argon-based detectors planned for DUNE are expected to be uniquely sensitive to the $\nu_e$ component of the supernova flux, enabling a wide variety of physics and astrophysics measurements. A key requirement for a correct interpretation of these measurements is a good understanding of the energy-dependent total cross section $\sigma(E_\nu)$ for charged-current $\nu_e$ absorption on argon. In the context of a simulated extraction of supernova $\nu_e$ spectral parameters from a toy analysis, we investigate the impact of $\sigma(E_\nu)$ modeling uncertainties on DUNE's supernova neutrino physics sensitivity for the first time. We find that the currently large theoretical uncertainties on $\sigma(E_\nu)$ must be substantially reduced before the $\nu_e$ flux parameters can be extracted reliably: in the absence of external constraints, a measurement of the integrated neutrino luminosity with less than 10\% bias with DUNE requires $\sigma(E_\nu)$ to be known to about 5%. The neutrino spectral shape parameters can be known to better than 10% for a 20% uncertainty on the cross-section scale, although they will be sensitive to uncertainties on the shape of $\sigma(E_\nu)$. A direct measurement of low-energy $\nu_e$-argon scattering would be invaluable for improving the theoretical precision to the needed level.Comment: 25 pages, 21 figure

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Sistema de tele-vigilancia domiciliaria para la promoción de la salud de pacientes con Insuficiencia Cardiaca

Premios: Ayudas a la Investidación Ignacio Larramendi, 201

Electrical performance of PEDOT:PSS-based textile electrodes for wearable ECG monitoring: a comparative study

Abstract Background Wearable textile electrodes for the detection of biopotentials are a promising tool for the monitoring and early diagnosis of chronic diseases. We present a comparative study of the electrical characteristics of four textile electrodes manufactured from common fabrics treated with a conductive polymer, a commercial fabric, and disposable Ag/AgCl electrodes. These characteristics will allow identifying the performance of the materials when used as ECG electrodes. The electrodes were subjected to different electrical tests, and complemented with conductivity calculations and microscopic images to determine their feasibility in the detection of ECG signals. Methods We evaluated four electrical characteristics: contact impedance, electrode polarization, noise, and long-term performance. We analyzed PEDOT:PSS treated fabrics based on cotton, cotton–polyester, lycra and polyester; also a commercial fabric made of silver-plated nylon Shielde® Med-Tex P130, and commercial Ag/AgCl electrodes. We calculated conductivity from the surface resistance and, analyzed their surface at a microscopic level. Rwizard was used in the statistical analysis. Results The results showed that textile electrodes treated with PEDOT:PSS are suitable for the detection of ECG signals. The error detecting features of the ECG signal was lower than 2% and the electrodes kept working properly after 36 h of continuous use. Even though the contact impedance and the polarization level in textile electrodes were greater than in commercial electrodes, these parameters did not affect the acquisition of the ECG signals. Fabrics conductivity calculations were consistent to the contact impedance

Home healthcare telemonitoring system for "medication titration" in the treatment of heart failure: Architecture for an interoperable solution

Heart failure is a common condition in which the heart is unable to keep up with its workload. Therefore, oxygen and nutrients are no longer able to reach the cardiac cells, which worsens the situation of the whole heart. Treating an HF patient is challenging due to the co-morbidities and the numerous medications associated with the treatment. Medical dosage through titration of ACE inhibitors (ACEIs), Angiotensin receptor blockers (ARBs), beta-blockers and other drugs is a recommended procedure to reduce morbidity and mortality in HF patients. However, the procedure is performed under medical supervision at the hospital, lasting from one to four weeks. We propose a telemonitoring system to help clinicians to follow the patient through the Medication Titration procedure at home. We used commercial medical devices, certified on international communication standards to assure interoperability. Independently of the producer or brand, they can operate properly in the designed architecture. So far, we are able to connect two medical devices, blood pressure meter and weight scale, to a data hub. Then the data is rerouted to the cloud, where information is stored in a database. We use a commercial application to visualize the data through a friendly graphical interface.A insuficiência cardíaca é uma condição comum na que o coração é incapaz de fornecer os volumes de sangue suficiente ao organismo. Portanto, o oxigénio e os nutrientes já não são capazes de chegar às células cardíacas, o que piora a situação de todo o coração. Tratar a um paciente com IC é um desafio devido às morbidades e os numerosos medicamentos associados com o tratamento. Dose médica através da titulação dos inibidores da ECA (IECA), bloqueadores dos receptores da angiotensina (ARA), beta bloqueadores e outros fármacos é um procedimento recomendado para reduzir a morbidade e a mortalidade nos pacientes com IC. No entanto, o procedimento realiza-se baixo supervisão médica no hospital, com uma duração de uma a quatro semanas. Propomos um sistema de telemonitoreo para ajudar aos médicos a seguir ao paciente através do processo de titulação de medicamentos em casa. Utilizamos dispositivos médicos comerciais, certificados em padrões internacionais de comunicação para assegurar a interoperabilidade. Independentemente do produtor ou a marca, eles podem funcionar corretamente na arquitetura desenhada. Até o momento, somos capazes de ligar dois dispositivos médicos, um medidor de pressão arterial e uma balança, a um concentrador de dados. A seguir, os dados são dirigidos à nuvem, onde a informação se aloja num banco de dados. Utilizamos um aplicativo comercial para visualizar os dados através de uma interface gráfica amigável.La insuficiencia cardíaca es una condición común en la que el corazón es incapaz de suministrar los volúmenes de sangre suficiente al organismo. Por lo tanto, el oxígeno y los nutrientes ya no son capaces de llegar a las células cardíacas, lo que empeora la situación de todo el corazón. Tratar a un paciente con IC es un desafío debido a las comorbilidades y los numerosos medicamentos asociados con el tratamiento. Dosis médica a través de la titulación de los inhibidores de la ECA (IECA), bloqueadores de los receptores de la angiotensina (ARA), beta bloqueadores y otros fármacos es un procedimiento recomendado para reducir la morbilidad y la mortalidad en los pacientes con IC. Sin embargo, el procedimiento se realiza bajo supervisión médica en el hospital, con una duración de una a cuatro semanas. Proponemos un sistema de telemonitoreo para ayudar a los médicos a seguir al paciente a través del proceso de titulación de medicamentos en casa. Utilizamos dispositivos médicos comerciales, certificados con estándares internacionales de comunicación para asegurar la interoperabilidad. Independientemente del productor o la marca, ellos pueden funcionar correctamente en la arquitectura diseñada. Hasta el momento, somos capaces de conectar dos dispositivos médicos, un medidor de presión arterial y una balanza, a un concentrador de datos. A continuación, los datos son redirigidos a la nube, donde la información se almacena en una base de datos. Utilizamos una aplicación comercial para visualizar los datos a través de una interfaz gráfica amigable

Techniques of Acquisition and Processing of Electrocardiographic Signals in the Detection of Cardiac Arrhythmias

The development of ambulatory monitoring systems and its electrocardiographic (ECG) signal processing techniques has become an important field of investigation, due to its relevance in the early detection of cardiovascular diseases such as the arrhythmias. The current trend of this technology is oriented to the use of portable equipment and mobile devices such as Smartphones, which have been widely accepted due to the technical characteristics and common integration in daily life. A fundamental characteristic of these systems is their ability to reduce the most common types of noise by means of digital signal processing techniques.  Among the most used techniques are the adaptive filters and the Discrete Wavelet Transform (DWT) which have been successfully implemented in several studies. There are systems that integrate classification stages based on artificial intelligence, which increases the performance in the process of arrhythmias detection. These techniques are not only evaluated for their functionality but for their computational cost, since they will be used in real-time applications, and implemented in embedded systems. This paper shows a review of each of the stages in the construction of a standard ambulatory monitoring system, for the contextualization of the reader in this type of technology