Poincaré Plot analysis and Graphical User Interface development for the study of Heart Rate Variability in asthmatic children

Asthma is a chronic lung disease that inflames and narrows the airways, and although it affects people of all ages it most often starts during childhood. However, there is still not a clinical method for the premature diagnosis of asthma, what makes it dependent on the doctor criteria. Some studies have shown that the pathophysiology of asthma is related with an abnormal ANS function that is responsible of bronchoconstriction. As ANS activity is reflected in HRV, the analysis of this HRV could lead to an interpretation of the physiologic processes underlying asthma, thus serving as a non-invasive way to diagnose it. It is nowadays agree that the several processes involved in HR control interact in a non-linear way and so non-linear analysis of HRV has received high research interest in the last years, so in this work the focus is on Poincaré plot analysis, which is one of the most representative non-linear HRV analysis techniques. Poincaré plot is a quantitative-visual technique extracted from non-linear dynamics, although the indexes extracted from it have been proven to not provide additional information to that obtained with other methods. Due to this fact, in this work a research in the origins of Poincaré plot has been attempted, in order to define new parameters that can display the non-linear characteristics of the plot. The angle of the plot and the short-term analysis of its shape were proposed, being the objective to find an index that can be used to classify a set of patients aged 3-7 years attending to their risk of suffering from asthma. Furthermore, a GUI was developed so that the information provided by Poincaré plots can be easily compared and integrated with the information extracted from several other indexes. Although the methods proposed for the extraction of the angle and the shape information were successful, the results obtained in this work showed that the use of both the classical HRV indexes and the new proposed parameters is not enough to stratify the risk of asthma in children. However, the GUI developed was shown to result useful when interpreting Poincaré plot information. Also a qualitative analysis of a Poincaré domain filtering technique proposed in the literature was performed, and several future work lines were established

Neighbourhood Modelling for Urban Sustainability Assessment

[EN] Climate change is becoming a dominant concern for advanced countries. The Paris Agreement sets out a global framework whose implementation relates to all human activities and is commonly guided by the United Nations Sustainable Development Goals (UN SDGs), which set the scene for sustainable development performance configuring all climate action related policies. Fast control of CO2 emissions necessarily involves cities since they are responsible for 70 percent of greenhouse gas emissions. SDG 11 (Sustainable cities and communities) is clearly involved in the deployment of SDG 13 (Climate Action). European Sustainability policies are financially guided by the European Green Deal for a climate neutral urban environment. In turn, a common framework for urban policy impact assessment must be based on architectural design tools, such as building certification, and common data repositories for standard digital building models. Many Neighbourhood Sustainability Assessment (NSA) tools have been developed but the growing availability of open data repositories for cities, together with big-data sources (provided through Internet of Things repositories), allow accurate neighbourhood simulations, or in other words, digital twins of neighbourhoods. These digital twins are excellent tools for policy impact assessment. After a careful analysis of current scientific literature, this paper provides a generic approach for a simple neighbourhood model developed from building physical parameters which meets relevant assessment requirements, while simultaneously being updated (and tested) against real open data repositories, and how this assessment is related to building certification tools. The proposal is validated by real data on energy consumption and on its application to the Benicalap neighbourhood in Valencia (Spain).This research was co-funded by the European Commission through the H2020 project "Green Cities for Climate and Water Resilience, Sustainable Economic Growth, Healthy Citizens and Environments (GROW GREEN)" Grant Agreement: 730283.Orozco-Messana, J.; Iborra Lucas, M.; Calabuig-Moreno, R. (2021). Neighbourhood Modelling for Urban Sustainability Assessment. Sustainability. 13(9):1-10. https://doi.org/10.3390/su13094654S11013

Combined Greening Strategies for Improved Results on Carbon-Neutral Urban Policies

[EN] Starting from historical environmental records of the Benicalap neighbourhood in Valencia, this paper presents an energy model contributing to the assessment of carbon-neutral city policies for several nature-based solution (NBS) pilots extended to the neighbourhood level and combined with building facade renovation proposals. Accurate monitoring of several NBS pilot strategies was studied to validate a computational-fluid-dynamic (CFD) microclimate flux (both storage heat flux and latent heat flux) model, allowing a joint understanding of humidity and heat dynamics for the pilots under study. When expanded at a neighbourhood level, the combined effect of NBSs and energy dynamics (from buildings and vegetation) on neighbourhood microclimates is used to assess the optimal combination of urban renovation policies for energy efficiency and consequently carbon footprint reduction.This research was co-funded by the European Commission through the H2020 project "Green Cities for Climate and Water Resilience, Sustainable Economic Growth, Healthy Citizens and Environments (GROW GREEN)" Grant Agreement: 730283Orozco-Messana, J.; Iborra Lucas, M.; Calabuig-Moreno, R. (2022). Combined Greening Strategies for Improved Results on Carbon-Neutral Urban Policies. Buildings. 12(7):1-13. https://doi.org/10.3390/buildings1207089411312

Noninvasive autonomic nervous system assessment in respiratory disorders and sport sciences applications

La presente tesis está centrada en el análisis no invasivo de señales cardíacas y respiratorias, con el objetivo de evaluar la actividad del sistema nervioso autónomo (ANS) en diferentes escenarios, tanto clínicos como no clínicos. El documento está estructurado en tres partes principales. La primera parte consiste en una introducción a los aspectos fisiológicos y metodológicos que serán cubiertos en el resto de la tesis. En la segunda parte, se analiza la variabilidad del ritmo cardiaco (HRV) en el contexto de enfermedades respiratorias, concretamente asma (tanto en niños como en adultos) y apnea del sueño. En la tercera parte, se estudian algunas aplicaciones novedosas del análisis de señales cardiorespiratorias en el campo de las ciencias del deporte. La primera parte está compuesta por los capítulos 1 y 2. El capítulo 1 consiste en una extensa introducción al funcionamiento del sistema nervioso autónomo y las características de las bioseñales analizadas a lo largo de la tesis. Por otro lado, se aborda la patofisiología del asma y la apnea del sueño, su relación con el funcionamiento del ANS y las estrategias de diagnóstico y tratamiento de lasmismas. El capítulo concluye con una introducción a la fisiología del ejercicio, así como al interés en la estimación del volumen tidal y del umbral anaeróbico en el campo de las ciencias del deporte.En cuanto al capítulo 2, se presenta un marco de trabajo para el análisis contextualizado de la HRV. Después de una descripción de las técnicas de evaluación y acondicionamiento de la señal de HRV, el capítulo se centra en el efecto de los latidos ectópicos, la arritmia sinusal respiratoria y la frecuencia respiratoria en el análisis de la HRV.Además, se discute el uso de un índice para la evaluación de la distribución de la potencia en los espectros de HRV, así como diferentes medidas de acoplo cardiorespiratorio.La segunda parte está compuesta por los capítulos 3, 4 y 5, todos ellos relacionados con el análisis de la HRV en enfermedades respiratorias. Mientras que los capítulos 3 y 4 están centrados en asma infantil y en adultos respectivamente, el capítulo 5 aborda la apnea del sueño. El asma es una enfermedad respiratoria crónica que aparece habitualmente acompañada por una inflamación de las vías respiratorias. Aunque afecta a personas detodas las edades, normalmente se inicia en edades tempranas, y ha llegado a constituir una de las enfermedades crónicasmás comunes durante la infancia. Sin embargo, todavía no existe un método adecuado para el diagnóstico de asma en niños pequeños. Por otro lado, el rol fundamental que desempeña el sistema nervioso parasimpático en el control del tono bronco-motor y la bronco-dilatación sugiere que la rama parasimpática del ANS podría estar implicada en la patogénesis del asma. De estemodo, en el capítulo 3 se evalúa el ANS mediante el análisis de la HRV en dos bases de datos diferentes, compuestas por niños en edad pre-escolar clasificados en función de su riesgo de desarrollar asma, o de su condición asmática actual. Los resultados del análisis revelaron un balance simpáticovagal reducido y una componente espectral de alta frecuencia más picuda en aquellos niños con un mayor riesgo de desarrollar asma. Además, la actividad parasimpática y el acoplo cardiorespiratorio se redujeron en un grupo de niños con bajo riesgo de asma al finalizar un tratamiento para bronquitis obstructiva, mientras que estos permanecieron inalterados en aquellos niños con una peor prógnosis.A diferencia de los niños pequeños, en el caso de adultos el diagnóstico de asma se realiza a través de una rutina clínica bien definida. Sin embargo, la estratificación de los pacientes en función de su grado de control de los síntomas se basa generalmente en el uso de cuestionarios auto-aplicados, que pueden tener un carácter subjetivo. Por otro lado, la evaluación de la severidad del asma requiere de una visita hospitalaria y de incómodas pruebas, que no pueden aplicarse de una forma continua en el tiempo. De este modo, en el capítulo 4 se estudia el valor de la evaluación del ANS para la estratificación de adultos asmáticos. Para ello, se emplearon diferentes características extraídas de la HRV y la respiración, junto con varios parámetros clínicos, para entrenar un conjunto de algoritmos de clasificación. La inclusión de características relacionadas con el ANS para clasificar los sujetos atendiendo a la severidad del asma derivó en resultados similares al caso de utilizar únicamente parámetros clínicos, superando el desempeño de estos últimos en algunos casos. Por lo tanto, la evaluación del ANS podría representar un potencial complemento para la mejora de la monitorización de sujetos asmáticos.En el capítulo 5, se analiza la HRV en sujetos que padecen el síndrome de apnea del sueño (SAS) y comorbididades cardíacas asociadas. El SAS se ha relacionado con un incremento de 5 veces en el riesgo de desarrollar enfermedades cardiovasculares (CVD), que podría aumentar hasta 11 veces si no se trata convenientemente. Por otro lado, una HRV alterada se ha relacionado independientemente con el SAS y con numerosos factores de riesgo para el desarrollo de CVD. De este modo, este capítulo se centra en evaluar si una actividad autónoma desbalanceada podría estar relacionada con el desarrollo de CVD en pacientes de SAS. Los resultados del análisis revelaron una dominancia simpática reducida en aquellos sujetos que padecían SAS y CVD, en comparación con aquellos sin CVD. Además, un análisis retrospectivo en una base de datos de sujetos con SAS que desarollarán CVD en el futuro también reveló una actividad simpática reducida, sugiriendo que un ANS desbalanceado podría constituir un factor de riesgo adicional para el desarrollo de CVD en pacientes de SAS.La tercera parte está formada por los capítulos 6 y 7, y está centrada en diferentes aplicaciones del análisis de señales cardiorespiratorias en el campo de las ciencias del deporte. El capítulo 6 aborda la estimación del volumen tidal (TV) a partir del electrocardiograma (ECG). A pesar de que una correcta monitorización de la actividad respiratoria es de gran interés en ciertas enfermedades respiratorias y en ciencias del deporte, la mayor parte de la actividad investigadora se ha centrado en la estimación de la frecuencia respiratoria, con sólo unos pocos estudios centrados en el TV, la mayoría de los cuales se basan en técnicas no relacionadas con el ECG. En este capítulo se propone un marco de trabajo para la estimación del TV en reposo y durante una prueba de esfuerzo en tapiz rodante utilizando únicamente parámetros derivados del ECG. Errores de estimación del 14% en la mayoría de los casos y del 6% en algunos sugieren que el TV puede estimarse a partir del ECG, incluso en condiciones no estacionarias.Por último, en el capítulo 7 se propone una metodología novedosa para la estimación del umbral anaeróbico (AT) a partir del análisis de las dinámicas de repolarización ventricular. El AT representa la frontera a partir de la cual el sistema cardiovascular limita la actividad física de resistencia, y aunque fue inicialmente concebido para la evaluación de la capacidad física de pacientes con CVD, también resulta de gran interés en el campo de las ciencias del deporte, permitiendo diseñar mejores rutinas de entrenamiento o para prevenir el sobre-entrenamiento. Sin embargo, la evaluación del AT requiere de técnicas invasivas o de dispositivos incómodos. En este capítulo, el AT fue estimado a partir del análisis de las variaciones de las dinámicas de repolarización ventricular durante una prueba de esfuerzo en cicloergómetro. Errores de estimación de 25 W, correspondientesa 1 minuto en este estudio, en un 63% de los sujetos (y menores que 50 W en un 74% de ellos) sugieren que el AT puede estimarse de manera no invasiva, utilizando únicamente registros de ECG.<br /

Análisis de regularidad morfológica de activaciones en señales EGM intracardiacas de pacientes con fibrilación auricular

La fibrilación auricular es la arritmia más común en nuestra sociedad y se caracteriza por una actividad eléctrica caótica de las aurículas. Puede provocar mortalidad a medio plazo por accidente cerebrovascular, insuficiencia cardiaca o infarto de miocardio. El objetivo del proyecto es estudiar un índice de regularidad basado en la morfología del EGM para la caracterización del tipo de fibrilación. La hipótesis de partida del trabajo es que la fibrilación auricular paroxística tiene una mayor organización que la fibrilación auricular persistente o permanente. Se propone implementar y evaluar un método de medida de la regularidad morfológica de la señal intracardiaca en contraposición a los índices clásicos basados en análisis espectral, que presentan problemas de dependencia con la frecuencia de activación

High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling

<p>Abstract</p> <p>Background</p> <p>The effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP) and subcutaneous (SC) adipose tissue, comparing fasted (F) to not fasted (NF) rats that had been fed a control or high-fat (HF) diet for 72 days.</p> <p>Methods</p> <p>Serum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4) were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test.</p> <p>Results</p> <p>High-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF) induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF) also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF) in animals fed either diet. In RP adipocytes of control animals, food intake (NF) decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF) did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF) decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet.</p> <p>Conclusions</p> <p>Animals fed a control-diet show a normal response to food intake (NF), with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase of caveolin-3 in muscle. Animals fed a high-fat diet develop metabolic changes that result in insulin signalling impairment. In these animals, caveolin expression in muscle and adipocytes seems to be regulated independently of insulin signalling.</p

Noninvasive cardiorespiratory signals analysis for asthma evolution monitoring in preschool children

Despite its increasing prevalence, diagnosis of asthma in children remains problematic due to their difficulties in producing repeatable spirometric maneuvers. Moreover, low adherence to inhaled corticosteroids (ICS) treatment could result in permanent airway remodeling. The growing interest in a noninvasive and objective way for monitoring asthma, together with the apparent role of autonomic nervous system (ANS) in its pathogenesis, have attracted interest towards heart rate variability (HRV) and cardiorespiratory coupling (CRC) analyses. In this work, HRV and CRC were analyzed in 70 children who were prescribed ICS treatment due to obstructive bronchitis. They underwent three different electrocardiogram and respiratory signals recordings, during and after treatment period. After treatment completion, they were followed up during 6 months and classified attending to their current asthma status. Vagal activity, as measured from HRV, and CRC, were reduced after treatment in those children at lower risk of asthma, whereas it kept unchanged in those with a worse prognosis. Results suggest that HRV analysis could be useful for the continuous monitoring of ANS anomalies present in asthma, thus contributing to evaluate the evolution of the disease, which is especially challenging in young children

Electrocardiogram-derived tidal volume during treadmill stress test

Objective: Electrocardiogram (ECG) has been regarded as a source of respiratory information with the main focus in the estimation of the respiratory rate. Although little research concerning the estimation of tidal volume (TV) has been conducted, there are several ECG-derived features that have been related with TV in the literature, such as ECG-derived respiration, heart rate variability or respiratory rate. In this work, we exploited these features for estimating TV using a linear model. Methods: 25 young (33.4 ± 5.2 years) healthy male volunteers were recruited for performing a maximal (MaxT) and a submaximal (SubT) treadmill stress test, which were conducted in different days. Both tests were automatically segmented in stages attending to the heart rate. Afterwards, a subject-specific TV model was calibrated for each stage, employing features from MaxT, and the model was later used for estimating the TV in SubT. Results: During exercise, the different proposed approaches led to relative fitting errors lower than 14% in most of the cases and than 6% in some of them. Conclusion: Low achieved fitting errors suggest that TV can be estimated from ECG during a treadmill stress test. Significance: The results suggest that it is possible to estimate TV during exercise using only ECG-derived features

Interplay of early-life nutritional programming on obesity, inflammation and epigenetic outcomes

The huge health burden accompanying obesity is not only attributable to inadequate dietary and sedentary lifestyle habits, since a predisposing genetic make-up and other putative determinants concerning easier weight gain and fat deposition have been reported. Thus, several investigations aiming to understand energy metabolism and body composition maintenance have been performed considering the participation of perinatal nutritional programming and epigenetic processes as well as inflammation phenomena. The Developmental Origins of Health and Disease hypothesis and inheritance-oriented investigations concerning gene–nutrient interactions on energy homoeostasis and metabolic functions have suggested that inflammation could be not only a comorbidity of obesity but also a cause. There are several examples about the role of nutritional interventions in pregnancy and lactation, such as energetic deprivation, protein restriction and excess fat, which determine a cluster of disorders affecting energy efficiency in the offspring as well as different metabolic pathways, which are mediated by epigenetics encompassing the chromatin information encrypted by DNA methylation patterns, histone covalent modifications and non-coding RNA or microRNA. Epigenetic mechanisms may be boosted or impaired by dietary and environmental factors in the mother, intergenerationally or transiently transmitted, and could be involved in the obesity and inflammation susceptibility in the offspring. The aims currently pursued are the early identification of epigenetic biomarkers concerned in individual's disease susceptibility and the description of protocols for tailored dietary treatments/advice to counterbalance adverse epigenomic events. These approaches will allow diagnosis and prognosis implementation and facilitate therapeutic strategies in a personalised ‘epigenomically modelled’ manner to combat obesity and inflammation