Now showing items 1-20 of 46

  • Accuracy of heart rate variability estimation by photoplethysmography using an smartphone : processing optimization and fiducial point selection 

    Ferrer Mileo, Víctor; Guede Fernández, Federico; Fernández Chimeno, Mireya; Ramos Castro, Juan José; García González, Miguel Ángel (Institute of Electrical and Electronics Engineers (IEEE), 2015)
    Conference report
    Open Access
    This work compares several fiducial points to detect the arrival of a new pulse in a photoplethysmographic signal using the built-in camera of smartphones or a photoplethysmograph. Also, an optimization process for ...
  • A comparison of heartbeat detectors for the seismocardiogram 

    García González, Miguel Ángel; Argelagós Palou, Ariadna; Fernández Chimeno, Mireya; Ramos Castro, Juan José (Institute of Electrical and Electronics Engineers (IEEE), 2013)
    Conference lecture
    Open Access
    The study aimed to study the accuracy in RR time series derived from the seismocardiogram when employing different heartbeat detectors in subjects measured in a quiet environment. The ECG and seismocardiogram of 17 healthy ...
  • A methodology to quantify the differences between alternative methods of heart rate variability measurement 

    García González, Miguel Ángel; Fernández Chimeno, Mireya; Guede Fernández, Federico; Ferrer Mileo, Víctor; Argelagós Palou, Ariadna; Álvarez Gómez, Laura; Parrado Romero, Eva; Moreno Sánchez, Jordi; Capdevila, Lluis; Ramos Castro, Juan José (Institute of Physics (IOP), 2015-12-14)
    Article
    Open Access
    This work proposes a systematic procedure to report the differences between heart rate variability time series obtained from alternative measurements reporting the spread and mean of the differences as well as the agreement ...
  • An application of fractional differintegration to heart rate variability time series 

    García González, Miguel Ángel; Fernández Chimeno, Mireya; Ramos Castro, Juan José; Capdevila, Lluis; Parrado, Eva (2013-07)
    Article
    Restricted access - publisher's policy
    Fractional differintegration is used as a new tool to characterize heart rate variability time series. This paper proposes and focuses in two indexes (ac and fnQ) derived from the fractional differintegration operator. ...
  • A new and fast index for the quantification of short range self-similarity in RR time series 

    García González, Miguel Ángel; Fernández Chimeno, Mireya; Ramos Castro, Juan José (2010)
    Conference lecture
    Open Access
    We propose a new and very fast index (the frequency of sign changes of the mirrored differences or fscmd) with good correlation with the short range scaling exponent (  R) estimated among scales 4 to 16 of the DFA. ...
  • A novel index based on fractional calculus to assess the dynamics of heart rate variability: changes due to chi or yoga meditations 

    García González, Miguel Ángel; Ramos Castro, Juan José; Fernández Chimeno, Mireya (Computing in Cardiology, 2012)
    Conference lecture
    Restricted access - publisher's policy
    The study aims to present and interpret a novel index based on fractional calculus ( αc) and to assess differences in RR time series dynamics in subjects during meditation. Fractional differintegration (FDI) of a RR time ...
  • A novel robust index to assess beat-to-beat variability in heart rate time-series analysis 

    García González, Miguel Ángel; Pallàs Areny, Ramon (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2001-06-30)
    Article
    Open Access
    A new index is proposed to estimate the variance of the differentiated heart rate (RR) time series from its truncated histogram. The index is more robust to artifacts than the standard deviation of the differentiated RR ...
  • Assessment of energy expended in physical activity by a smartphone-based system 

    Guede Fernández, Federico; Carbones Fargas, Bernat; Capdevila Ortis, Lluís; García González, Miguel Ángel; Ramos Castro, Juan José; Fernández Chimeno, Mireya (Springer, 2014)
    Conference report
    Restricted access - publisher's policy
    The aim of this paper is to present a smartphone based system to assess daily energy expended in physical activ- ity (PA). Nowadays, sedentary li festyle is increasingly recog- nized as a serious, worldwide public ...
  • A wireless under-mattress sensor system for sleep monitoring in people with major depression 

    Mahdavi, Hadiseh; Ramos Castro, Juan José; Giovinazzo, Giuseppe; García González, Miguel Ángel; Rosell Ferrer, Francisco Javier (2012)
    Conference report
    Restricted access - publisher's policy
    Monitoring people during sleep time is of particular interest to patients with sleep disorders and elderly people or infants. We have developed a battery powered electronic system to monitor people in the bed, store the ...
  • Changes in heart rate variability indexes due to drowsiness in professional drivers measured in a real environment 

    García González, Miguel Ángel; Fernández Chimeno, Mireya; Ramos Castro, Juan José (Computing in Cardiology, 2012)
    Conference lecture
    Restricted access - publisher's policy
    The study aims to assess the changes in Heart Rate Variability (HRV) indexes in healthy subjects whi le driving in a real environment in order to detect drowsiness. The ECG of ten professional drivers was acquired ...
  • Comparison of omega wave system and polar S810i to detect R-R intervals at rest 

    Parrado Romero, Eva; García González, Miguel Ángel; Ramos Castro, Juan José; Cervantes Blasquez, Julio Cesar; Rodas Font, Gil; Capdevila Ortis, Lluís (2010)
    Article
    Restricted access - publisher's policy
    The present study was performed to compare R-R interval data and heart rate variability indices obtained from the Polar S810i and the Omega Wave Sport System for a total of 96 adults in a supine position. Data were ...
  • Comparison of video-based methods for respiration rhythm measurement 

    Mateu Mateus, Marc; Guede Fernández, Federico; Ferrer Mileo, Víctor; García González, Miguel Ángel; Ramos Castro, Juan José; Fernández Chimeno, Mireya (2019-05-01)
    Article
    Restricted access - publisher's policy
    The aim of this work is to characterize the di erences in the respiratory rhythm obtained through three video based methods by comparing the obtained respiratory signals with the one obtained with the gold standard method ...
  • Contactless electrical bioimpedance system for monitoring ventilation. A biodevice for vehicle environment 

    Macías Macías, Raúl; García González, Miguel Ángel; Ramos Castro, Juan José; Bragós Bardia, Ramon; Fernández Chimeno, Mireya (SciTePress, 2013)
    Conference report
    Restricted access - publisher's policy
    Nowadays, automotive companies are focused in improving road traffic safety. For that, not only the vehicle performance is improved but also the driver behavior is monitored. This could be done in many ways. One of them ...
  • Development of a system to test somnolence detectors with drowsy drivers 

    Lopez De la O, Jaime; Rodriguez Ibañez, Noelia; Nombela, Mario; Barrios, Jose Manuel; García González, Miguel Ángel; Ramos Castro, Juan José; Fernández Chimeno, Mireya (2012)
    Article
    Restricted access - publisher's policy
  • Differences in QRS locations due to ECG lead: relationship with breathing 

    García González, Miguel Ángel; Argelagós Palou, Ariadna; Fernández Chimeno, Mireya; Ramos Castro, Juan José (2013)
    Conference report
    Restricted access - publisher's policy
    Results of heart rate variability analysis depend on the accuracy of the RR time series that is measured only in one lead of the ECG. RR time series can subtly change from lead to lead. We have obtained the ECG of 21 healthy ...
  • Driver drowsiness detection based on respiratory signal analysis 

    Guede Fernández, Federico; Fernández Chimeno, Mireya; Ramos Castro, Juan José; García González, Miguel Ángel (Institute of Electrical and Electronics Engineers (IEEE), 2019-06-24)
    Article
    Open Access
    Drowsy driving is a prevalent and serious public health issue that deserves attention. Recent studies estimate around 20% of car crashes have been caused by drowsy drivers. Nowadays, one of the main goals in the development ...
  • Drowsiness detection by thoracic effort signal analysis in real driving environments 

    Rodriguez Ibáñez, Noelia; García González, Miguel Ángel; Fernández Chimeno, Mireya; Ramos Castro, Juan José (2011)
    Conference lecture
    Restricted access - publisher's policy
    Detection of drowsiness while driving is a leading objective in advanced driver assistance systems. This work presents a new index to assess the alertness state of drivers based on the respiratory ...
  • Drowsiness detection by thoracic effort signal snalysis with professional drivers in real environments 

    Rodriguez Ibañez, Noelia; García González, Miguel Ángel; Ramos Castro, Juan José; Fernández Chimeno, Mireya (2011)
    Conference report
    Open Access
    Objective : The aim of this work is to develop a new index to assess the alertness state of drivers based on the respiratory dynamics derived f rom an inductive band. Background : Detection of drowsiness while driving ...
  • Effect of vibration frequency on agonist and antagonist arm muscle activity 

    Rodríguez Jiménez, Sergio; Benítez Herrera, Adolfo; García González, Miguel Ángel; Moras-Feliu, Gerard; Maffiuletti, Nicola A. (2015-01-23)
    Article
    Open Access
    Purpose This study aimed to assess the effect of vibration frequency (fout) on the electromyographic (EMG) activity of the biceps brachii (BB) and triceps brachii (TB) muscles when acting as agonist and antagonist during ...
  • Estimation of the uncertainty in time domain indices of RR time series 

    García González, Miguel Ángel; Fernández Chimeno, Mireya; Ramos Castro, Juan José (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2007-03-31)
    Article
    Open Access
    A method for estimating the uncertainty in time-domain indices of RR time series is described. The method relies on the central limit theorem that states that the distribution of a sample average of independent samples has ...