Pablo Laguna

Pablo Laguna
University of Zaragoza | UNIZAR · Engineering Research Institute of Aragon

Ph.D.

About

539
Publications
79,674
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12,777
Citations
Citations since 2017
133 Research Items
5811 Citations
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201720182019202020212022202302004006008001,000
201720182019202020212022202302004006008001,000

Publications

Publications (539)
Article
- Heart rate variability (HRV) is modulated by sleep stages and apneic events. Previous studies in children compared classical HRV parameters during sleep stages between obstructive sleep apnea (OSA) and controls. However, HRV-based characterization incorporating both sleep stages and apneic events has not been conducted. Furthermore, recently prop...
Article
Full-text available
The multidimensionality of the stress response has shown the complexity of this phenomenon and therefore the impossibility of finding a unique biomarker among the physiological variables related to stress. An experimental study was designed and performed to guarantee the correct synchronous and concurrent measure of psychometric tests, biochemical...
Article
The tools for spectrally analyzing heart rate variability (HRV) has in recent years grown considerably, with emphasis on the handling of time-varying conditions and confounding factors. Time-frequency analysis holds since long an important position in HRV analysis, however, this technique cannot alone handle a mean heart rate or a respiratory frequ...
Article
Full-text available
Pulse photoplethysmography (PPG) is a simple and economical technique for obtaining cardiovascular information. In fact, PPG has become a very popular technology among wearable devices. However, the PPG signal is well-known to be very vulnerable to artifacts, and a good quality signal cannot be expected for most of the time in daily life. The perce...
Article
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Atrial fibrosis plays a key role in the initiation and progression of atrial fibrillation (AF). Atrial fibrosis is typically identified by a peak-to-peak amplitude of bipolar electrograms (b-EGMs) lower than 0.5 mV, which may be considered as ablation targets. Nevertheless, this approach disregards signal spatiotemporal information and b-EGM sensit...
Article
Full-text available
Heart rate variability (HRV) has been studied for decades in clinical environments. Currently, the exponential growth of wearable devices in health monitoring is leading to new challenges that need to be solved. These devices have relatively poor signal quality and are affected by numerous motion artifacts, with data loss being the main stumbling b...
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Objective: T-wave alternans (TWA) manifests as beat-to-beat fluctuations of T-wave morphology on the electrocardiogram (ECG), with physiological bases not fully understood. Using a biophysical model of the ECG, we demonstrate and give explicit relations that TWA depends on the i) spatial covariance between myocytes' repolarization time and alterna...
Article
Full-text available
The spatial QRS-T angle is a promising health indicator for risk stratification of sudden cardiac death (SCD). Thus far, the angle is estimated solely from 12-lead electrocardiogram (ECG) systems uncomfortable for ambulatory monitoring. Methods to estimate QRS-T angles from reduced-lead ECGs registered with consumer healthcare devices would, theref...
Article
Se propone un nuevo índice para la estratificación de la apnea del sueño. Este índice se basa en la detección de las frecuencias a las que se producen las variaciones cíclicas de la frecuencia cardíaca (CVHR) en los segmentos con respiración anormal. También se propone un detector de CVHR. Cuando se utiliza conjuntamente con este detector, el índic...
Article
Pacientes con crecimiento intrauterino retardado (CIR) presentan variaciones anatómicas y electrofisiológicas en el corazón y su relación todavía no se conoce. Este estudio investiga mediante simulación computacional el impacto del aumento del índice de esfericidad ventricular y se valida con el cambio en los vectores de la despolarización y repola...
Article
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Objective: Non-invasive estimation of serum potassium, [K+], and calcium, [Ca2+], can help to prevent life-threatening ventricular arrhythmias in patients with advanced renal disease, but current methods for estimation of electrolyte levels have limitations. We aimed to develop new markers based on the morphology of the QRS complex of the electroc...
Article
Objective: The clinical significance of QT interval adaptation to heart rate changes has been poorly investigated in atrial fibrillation (AF), since QT delineation in the presence of f-waves is challenging. The objective of the present study is to investigate new techniques for QT adaptation estimation in permanent AF. Methods: A multilead strat...
Article
Background: T-wave (TW) morphology indices based on time-warping ( dw) have shown significant cardiovascular risk stratification value. However, errors in the location of TW boundaries may impact their prognostic power. Our aim was to test the hypothesis that a weighted time-warping function (WF) would reduce the sensitivity of dw to these errors...
Article
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Objective Noninvasive screening of hypo- and hyperkalemia can prevent fatal arrhythmia in end-stage renal disease (ESRD) patients, but current methods for monitoring of serum potassium (K+) have important limitations. We investigated changes in nonlinear dynamics and morphology of the T wave in the electrocardiogram (ECG) of ESRD patients during he...
Article
Stress test electrocardiogram (ECG) analysis is widely used for coronary artery disease (CAD) diagnosis despite its limited accuracy. Alterations in autonomic modulation of cardiac electrical activity have been reported in CAD patients during acute ischemia. We hypothesized that those alterations could be reflected in changes in ventricular repolar...
Article
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The present paper proposes the design of a sleep monitoring platform. It consists of an entire sleep monitoring system based on a smart glove sensor called UpNEA worn during the night for signals acquisition, a mobile application, and a remote server called AeneA for cloud computing. UpNEA acquires a 3-axis accelerometer signal, a photoplethysmogra...
Article
Se pretende mejorar la detección del final de la onda T (Te) de la señal de electrocardiograma (ECG) grabada durante prueba de esfuerzo. Así, los puntos Te se calculan en la primera derivación transformada de los métodos PCA y piCA, y se comparan con losextraídos directamente del ECG.
Article
La fibrosis auricular representa un papel clave en la patogenia de la fibrilación auricular, y es un factor importante para el guiado de procedimientos de ablación con catéter. Se consideran fibróticas las áreas cuyos electrogramas bipolares (b-EGMs) presentan una amplitud pico-a-pico inferior a 0.5 mV [1]. Sin embargo, la amplitud de dichas señale...
Article
Noninvasive estimation of serum potassium concentration can help prevent ventricular arrhythmias and sudden cardiac death in patients with chronic renal failure (CKD), but current outpatient estimation methods are limited. In this study, we estimated serum potassium concentration by evaluating the slopes of the “QRS complex” of the electrocardiogra...
Conference Paper
The present study investigates the differences in autonomic nervous system (ANS) function and stress response between patients with major depressive disorder (MDD) and healthy subjects by measuring changes in ANS biomarkers. ANS-related parameters are derived from various biosignals during a mental stress protocol consisting of a basal, stress, and...
Article
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Introduction: The omnipolar electrogram method was recently proposed to try to generate orientation-independent electrograms. It estimates the electric field from the bipolar electrograms of a clique, under the assumption of locally plane and homogeneous propagation. The local electric field evolution over time describes a loop trajectory from whic...
Article
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The autonomic nervous system (ANS) plays an essential role in the generation and maintenance of cardiac arrhythmias. The cardiac ANS can be divided into its extrinsic and intrinsic components, with the latter being organized in an epicardial neural network of interconnecting axons and clusters of autonomic ganglia called ganglionated plexi (GPs). G...
Article
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The ideal moment to withdraw respiratory supply of patients under Mechanical Ventilation at Intensive Care Units (ICU), is not easy to be determined for clinicians. Although the Spontaneous Breathing Trial (SBT) provides a measure of the patients’ readiness, there is still around 15–20% of predictive failure rate. This work is a proof of concept fo...
Article
Objective the aim of this study is to evaluate whether noninvasive autonomic activity assessment could represent a potential tool for the stratification of asthmatic subjects based on symptoms control, using only 10-min electrocardiographic and respiratory signals. Methods several heart rate variability (HRV) derived indexes, which are regarded as...
Article
Full-text available
Objective The aim of this study is to compare the performance of two electrocardiogram (ECG) lead-space reduction (LSR) techniques in generating a transformed ECG lead from which T-wave morphology markers can be reliably derived to non-invasively monitor blood potassium concentration ([K+]) in end-stage renal disease (ESRD) patients undergoing hemo...
Article
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Background: End-stage renal disease patients undergoing hemodialysis (ESRD-HD) therapy are highly susceptible to malignant ventricular arrhythmias caused by undetected potassium concentration ([K+]) variations (Δ[K+]) out of normal ranges. Therefore, a reliable method for continuous, noninvasive monitoring of [K+] is crucial. The morphology of the...
Article
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Background Atrial fibrillation (AF) is the most common supraventricular arrhythmia characterized by disorganized atrial electrical activity, maintained by localized arrhythmogenic atrial drivers. Pulmonary vein isolation (PVI) allows to exclude PV-related drivers. However, PVI is less effective in patients with additional extra-PV arrhythmogenic dr...
Article
Full-text available
We investigated the ability of time-warping-based ECG-derived markers of T-wave morphology changes in time (dw) and amplitude (da), as well as their non-linear components (dwNL and daNL), and the heart rate corrected counterpart (dw,c), to monitor potassium concentration ([K+]) changes (Δ[K+]) in end-stage renal disease (ESRD) patients undergoing h...
Preprint
Full-text available
Background: End-stage renal disease (ESRD) patients undergoing hemodyalisis therapy (HD) experience blood potassium ([K + ]) variations that are reflected on the T-wave (TW) morphology. Methods: We evaluated the performance of different lead space reduction (LSR) methods: principal component analysis (PCA), maximising the TW energy, and two derived...
Article
Actualmente, la Prueba de Respiración Espontánea (SBT), indica si un paciente está listo para el destete de la ventilación mecánica. Sin embargo, en torno al 20% de los pacientes “preparados” para ser desintubados, realmente no lo estaban. En este trabajo, se ha estudiado la Capacidad del Barorreflejo durante la hora anterior a la SBT, y se ha vist...
Article
En este trabajo se proponen marcadores no invasivos para estratificar pacientes según su riesgo de sufrir arritmias ventriculares que pueden desencadenar en muerte súbita cardiaca. Estos marcadores se basan en la respuesta del intervalo QT del ECG durante la prueba de esfuerzo, donde los cambios del ritmo cardiaco tienen un rango mayor de variación...
Article
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Objective: Chronic kidney disease affects more than 10% of the world population. Changes in serum ion concentrations increase the risk for ventricular arrhythmias and sudden cardiac death, particularly in end-stage renal disease (ESRD) patients. We characterized how T wave amplitude, duration and morphology descriptors change with variations in ser...
Preprint
Full-text available
The ideal moment to withdraw respiratory supply of patients under Mechanical Ventilation (MV) at Intensive Care Units (ICU), is not easy to be determined for clinicians. Although the Spontaneous Breathing Trial (SBT) provides a measure of the patients’ readiness, there is still around 15-20% of predictive failure rate. This work explores both Heart...
Article
Full-text available
Hemodialysis patients are susceptible to life-threatening arrhythmias whose incidence is markedly higher during the long interdialytic interval due to electrolyte fluctuations. Noninvasive monitoring of electrolyte fluctuations, particularly those of potassium, would enable restoring electrolyte balance before the onset of arrhythmias. This study i...
Conference Paper
Full-text available
Atrial fibrillation (AF) is the most frequent irregular heart rhythm due to disorganized atrial electrical activity, often sustained by rotational drivers called rotors. The non-invasive localization of AF drivers can lead to improved personalized ablation strategy, suggesting pulmonary vein (PV) isolation or more complex extra-PV ablation procedur...
Article
In this work, a detection and classification method for sleep apnea and hypopnea, using photopletysmography (PPG) and peripheral oxygen saturation ( $SpO_2$ ) signals, is proposed. The detector consists of two parts: one that detects reductions in amplitude fluctuation of PPG (DAP) and one that detects oxygen desaturations. To further differentiat...
Article
Objective: In the present study, a photoplethysmographic (PPG) waveform analysis for assessing differences in autonomic reactivity to mental stress between patients with Major Depressive Disorder (MDD) and healthy control (HC) subjects is presented. Methods: PPG recordings of 40 MDD and 40 HC subjects were acquired at basal conditions, during th...
Conference Paper
Full-text available
Weaning is the process of withdrawing mechanical ventilation at the Intensive Care Units. The problem is that around 20% of weaned patients were not actually ready for discontinuation. Studies suggest that vagal dysfunc-tion is lower in patients successfully weaned. Therefore, the Baroreflex Sensitivity (BRS) and Heart Rate Variability (HRV) are es...
Conference Paper
Full-text available
There is increasing evidence on the role of the autonomic nervous system in the pathogenesis of atrial fibrillation. Interventions targeting autonomic modulation of atrial electrical activity have been shown to reduce the incidence of atrial arrhythmias. Additionally, recent investigations have proved that pharmacological therapies inhibiting small...
Conference Paper
A pilot study on tracking changes in tidal volume (TV) using ECG signals acquired by a wearable armband is presented. The wearable armband provides three ECG channels by using three pairs of dry electrodes, resulting in a device that is convenient for long-term daily monitoring. An additional ECG channel was derived by computing the first principal...
Article
A method for deriving respiratory rate from an armband, which records three-channel electrocardiogram (ECG) using three pairs of dry (no hydrogel) electrodes, is presented. The armband device is especially convenient for long-term (months-years) monitoring because it does not use obstructive leads nor hydrogels/adhesives, which cause skin irritatio...
Article
Full-text available
Background: Voltage mapping allows identifying the arrhythmogenic substrate during scar-related ventricular arrhythmia (VA) ablation procedures. Slow conducting channels (SCCs), defined by the presence of electrogram (EGM) signals with delayed components (EGM-DC), are responsible for sustaining VAs and constitute potential ablation targets. Howeve...
Article
Full-text available
Objective: Elevated spatio-temporal variability of human ventricular repolarization has been related to increased risk for ventricular arrhythmias and sudden cardiac death, particularly under β-adrenergic stimulation (β-AS). This work presents a methodology for theoretical characterization of temporal and spatial repolarization variability at base...
Article
Full-text available
Cardiorespiratory monitoring is crucial for the diagnosis and management of multiple conditions such as stress and sleep disorders. Therefore, the development of ambulatory systems providing continuous, comfortable, and inexpensive means for monitoring represents an important research topic. Several techniques have been proposed in the literature t...