0000000001227649
AUTHOR
Nuria Ortigosa
showing 7 related works from this author
Cluster-Based Relocation of Stations for Efficient Forest Fire Management in the Province of Valencia (Spain)
2021
Forest fires are undesirable situations with tremendous impacts on wildlife and people&rsquo
Functional Data Analysis for ECG Recordings of Paroxysmal Atrial Fibrillation Patients Before and After Pulmonary Vein Isolation
2018
Pulmonary vein isolation is the cornestone of current ablation techniques for patients with paroxysmal atrial fibrillation in order avoid recurrences of the arrhythmia and maintain sinus rhythm. This study aimed to analyse the existence of significant variations in surface ECG after pulmonary vein isolation by means of functional data analysis. 12 consecutive unselected patients suffering from paroxysmal atrial fibrillation who underwent catheter ablation were included in the study. Each patient was monitored in sinus rhythm before and after catheter ablation. P-waves of bipolar lead II were delineated. Functional data were fitted from these segments and the first and second derivatives eva…
Gabor frames for classification of paroxysmal and persistent atrial fibrillation episodes
2016
[EN] In this study, we propose a new classification method for early differentiation of paroxysmal and persistent atrial fibrillation episodes, i.e. those which spontaneously or with external intervention will return to sinus rhythm within 7 days of onset from the ones where the arrhythmia is sustained for more than 7 days. Today, clinicians provide patients classification once the course of the arrhythmia has been disclosed. This classification problem is dealt with in this study. We study a sparse representation of surface electrocardiogram signals by means of Gabor frames and afterwards we apply a linear discriminant analysis. Thus, we provide an early discrimination, obtaining promising…
Predictive analysis of Cardiac Resynchronization Therapy response by means of the ECG
2016
Aims: Cardiac Resynchronization Therapy (CRT) is an effective treatment for heart failure patients with moderate to severe symptoms. Unfortunately, a significant proportion of patients (up to 35%) do not respond to CRT (patients called "non-responders"). This results in a large cost-effectiveness relation for heart failure treatment. This study aims to assess the prediction response to CRT by means of analysing the ECG. Methods: We retrospectively analysed the surface ECG and QRS previous to CRT implantation in 45 consecutive patients with dilated (27) or ischemic (18) cardiomyopathy. We extracted the QRS and then processed a measure of energy of a discrete version of the Stockwell Transfor…
Time-frequency analysis for early classification of persistent and long-standing persistent atrial fibrillation
2016
This study aimed to assess an early classification of persistent and long-standing persistent atrial fibrillation patients by means of the time-frequency analysis of the surface ECG, which would allow electrophysiologists to choose the most suitable therapeutic approach to treat this arrhythmia. 140 consecutive unselected patients suffering from atrial fibrillation conformed the study population (84 persistent and 56 long-standing persistent). After ventricular activity cancellation, time-frequency analysis of the atrial activity was performed. Then, the study of phase variations along time for those frequency bands where the average power of atrial activity is concentrated, together with t…
Phase information of time-frequency transforms as a key feature for classification of atrial fibrillation episodes
2015
[EN] Patients suffering from atrial fibrillation can be classified into different subtypes, according to the temporal pattern of the arrhythmia and its recurrence. Nowadays, clinicians cannot differentiate a priori between the different subtypes, and patient classification is done afterwards, when its clinical course is available. In this paper we present a comparison of classification performances when differentiating paroxysmal and persistent atrial fibrillation episodes by means of support vector machines. We analyze short surface electrocardiogram recordings by extracting modulus and phase features from several time-frequency transforms: short-time Fourier transform, Wigner-Ville, Choi-…
Primera experiencia y presentación de labores investigadoras referentes a análisis de imágenes médicas para alumnos de enseñanzas medias
2019
Los Campus Científicos de Verano tienen como objetivo que los alumnos de enseñanzas medias de las opciones científico-técnicas tengan un primer contacto con la labor investigadora que se realiza en las universidades y centros de investigación. Para ello, los estudiantes participan en proyectos de una semana de duración organizados en diferentes sesiones, como la presentada en este trabajo. Enmarcado en el proyecto “Tecnología y física médicas: la innovación al servicio de la medicina”, cuyo objetivo es fomentar el interés de los alumnos en las aplicaciones tecnológicas de la ingeniería biomédica, presentamos un seminario sobre técnicas de análisis de imágenes biomédicas mediante la utilizac…