Publications de Jean-Marc Vesin

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Introduction: We recently observed in human left atrium periods of intermittent 2:1 and 1:1 atrial capture, preceded by atrial repolarization alternans (Re-ALT) during rapid pacing. It remains undetermined whether Re- ALT plays a role in preventing 1:1 atrial capture over long periods of rapid pacing. Methods: We specifically developed a chronic ovine model of rapid atrial pacing using two pacemakers (PM) each with a single right atrial (RA) lead separated by ~2 cm. The 1st PM was used to record a broadband

In recent years, wearable photoplethysmographic (PPG) biosensors have emerged as promising tools to monitor heart rate (HR) during physical exercise. However, PPG waveforms are easily corrupted by motion artifacts, rendering HR estimation difficult. In thi ...

Introduction: It has been shown that repolarization alternans (Re-ALT), a beat-to-beat alternation in action potential duration, enhances dispersion of repolarization DOR above a critical heart rate and promotes susceptibility to ventricular arrhythmias. It is unknown whether Re-ALT is measurable in the atria using standard pacemakers and whether Re-ALT plays a role in promoting AF. Methods: two DDD pacemakers (PM) with two right atrial (RA) leads were implanted in 3 male sheep (>60kg) after ablation of the

The detection of stable atrial fibrillation (AF) sources remains one of the major challenges in the AF management. In this study, we investigated the feasibility of detecting stable AF sources from (non invasive) data simulated by means of numerical proced ...

The proposed study investigates a phenomenon, defined as "U-patterns", that takes place in the RR-interval time series during sleep. These patterns are defined as a U-shaped decrease-increase in the RR-intervals, with a duration of 20 to 40 seconds with a ...

Introduction: We hypothesized that organization indices based on the analysis of atrial ECG harmonic components may help identify patients (pts) with persistent AF (pAF) unresponsive to pulmonary vein isolation (PVI) and left atrial (LA) ablation. Using adaptive harmonic frequency tracking schemes, we computed on the atrial ECG: 1) the variance of the phase difference (aPD) between the dominant frequency (DF) and the 1st harmonic (H1), and 2) the organization index (AOI) defined as the ratio of the power of

Few data are available on the assessment of P-wave beat-to-beat morphology variability and its ability to identify patients prone to paroxysmal atrial fibrillation (AF) occurrence. Aim of this study was to determine whether electrocardiographic (ECG) param ...

We studied the mechanisms of spontaneous termination of atrial fibrillation in a biophysical model of human atria, during the eight seconds preceding termination. The earliest detectable changes in the cycle length and the number of wavefronts occurred abo ...

Heart rate variability (HRV) is non-invasive and commonly used for monitoring responses to training loads, fitness, or overreaching in athletes. Yet, the recording duration for aseries of RR-intervals varies from 1 to 15 min in the literature. The aim of t ...

Preliminary studies showed that the septum area was the only location allowing local capture of both the atria during rapid pacing of atrial fibrillation (AF) from a single site. The present model-based study investigated the influence of atrial substrate ...

The standard ECG remains the most common non-invasive tool for assessing atrial fibrillation. Specific signal processing techniques have been developed to improve the diagnosis. However, validation of such tools is challenging and comprehensive invasive da ...

Various approaches have been proposed to detect the R-waves in the ECG. From the derivative-based to more complicated wavelet transform methods, the main goal of these approaches is to extract the R-waves from the perturbations present in the ECG. Our study aims at proposing a simple preprocessing tool that suppresses perturbations and enhances the R-waves in the ECG. Using sliding windows, short- and long-term signal energies are calculated for each sample in the ECG. A coefficient signal is then created a

Imaging photoplethysmography (iPPG) has gained a lot of popularity as a contactless heart rate (HR) monitoring technique. However, most of the existing approaches to estimate HR are based on block-wise processing schemes, which are not optimal for real-time applications. The aim of this study was to investigate robust HR estimation methods having a short estimation delay, which would be suitable for real-time HR monitoring applications using iPPG. The three following algorithms were evaluated: 1) an algorit

Estimating the respiratory rate (RR) from the electrocardiogram (ECG) is of interest as the direct measurement of the respiration in clinical situations is often cumbersome. In this study, the RR was estimated from the multi-lead ECG R-peak amplitude (RPA) waveforms, which contain the modulation of the cardiac activity by the respiration. An adaptive oscillator-based frequency tracking algorithm was used to estimate the RR from the RPAs of two or three ECG leads. This automatic and instantaneous method trac

The respiratory rate is an important vital sign that needs to be monitored continuously in clinical and non-clinical health monitoring applications. It is commonly estimated from electrocardiogram (ECG)-derived respiratory waveforms such as the respiratory sinus arrhythmia~(RSA) and the ECG R peak amplitude~(RPA). Current methods combine respiratory information from these two waveforms but produce large delays in estimating the respiratory rate. In this work, the power of the outputs of a bank of order-3 FI

This paper explores a novel approach for ventricular and atrial activities estimation in electrocardiogram (ECG) signals, based on sparse source separation. Sparse decompositions of ECG over signal-adapted multi-component dictionaries can lead to natural separation of its components. In this work, dictionaries of functions adapted to ventricular and atrial activities are respectively defined. Then, the weighted orthogonal matching pursuit algorithm is used to unmix the two components of ECG signals. Despite

Gradient boosting is a machine learning method, that builds one strong classifier from many weak classifiers. In this work, an algorithm based on gradient boosting is presented, that detects event-related potentials in single electroencephalogram (EEG) trials. The algorithm is used to detect the P300 in the human EEG and to build a brain-computer interface (BCI), specifically a spelling device. Important features of the method described here are its high classification accuracy and its conceptual simplicity

This paper discusses the problems raised by the optimization of a mutual information-based objective function, in the context of a multimodal speaker detection. As no approximation is used, this function is highly nonlinear and plagued by numerous local minima. Three different optimization methods are compared. The Differential Evolution algorithm is deemed to be the best for the problem at hand and, consequently, is used to perform the speaker detection.

Olfactory perception is a complex phenomenon associated with other processes such as cognition and emotion. Due to this complexity, there are still open issues and challenges regarding olfactory psychophysiology. One challenge concerns the investigation of ...

Our study aims at determining whether the efficiency of step-wise catheter ablation (step-CA) of persistent atrial fibrillation (pAF) can be tracked using organization indices based on the harmonic components of atrial ECG signals until pAF termination. ECG time series devoid of QRST were recorded at baseline (pre-ablation), after pulmonary vein isolation and at the end of left atrium (LA) ablation. Using adaptive harmonic frequency tracking schemes, two organisation indices characterizing the relationship

Jean-Marc Vesin

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Decreased Excitability as a Protective Mechanism Against Repolarization Alternans-Induced Atrial Reentry

Adaptive Frequency Tracking for Robust Heart Rate Estimation Using Wrist-Type Photoplethysmographic Signals During Physical Exercise

In-Vivo Measurements of Atrial Repolarization Alternans Based on Standard Pacemaker Technology

Adaptive Multiple Frequency Tracking Algorithm: Detection of Stable Atrial Fibrillation Sources from Standard 12-Lead ECG

Analysis of U-Shape Patterns in RR-Interval Time Series During Sleep

Adaptive harmonic frequency schemes of atrial ECG reveal divergent patterns of organization during catheter ablation of persistent atrial fibrillation

Usefulness of P-Wave Duration and Morphologic Variability to Identify Patients Prone to Paroxysmal Atrial Fibrillation

Spontaneous termination of atrial fibrillation: study of the effect of atrial geometry in a biophysical model

Minimal Window Duration for Accurate HRV Recording in Athletes

Influence of atrial substrate on local capture induced by rapid pacing of atrial fibrillation

The Role of Atrial Modeling in the Development of ECG Processing Tools

A Novel Preprocessing Tool to Enhance ECG R-wave Extraction

Real-Time Approaches for Heart Rate Monitoring using Imaging Photoplethysmography

Respiratory Rate Estimation from Multi-Lead ECGs using an Adaptive Frequency Tracking Algorithm

Estimating the real-time respiratory rate from the ECG with a bank of notch filters

Ventricular and Atrial Activity Estimation Through Sparse ECG Signal Decompositions

A Boosting Approach to P300 Detection with Application to Brain-Computer Interfaces

Differential Evolution applied to a multimodal information theoretic optimization problem

Multivariate Spectral Analysis for Identifying the Brain Activations During Olfactory Perception

Prediction of Atrial Fibrillation Termination by Catheter Ablation Using Adaptive Frequency Tracking of Atrial ECG Signal