Now showing items 1-20 of 83

  • AC-coupled front-end for biopotential measurements 

    Spinelli, Enrique M.; Mayosky, Miguel Ángel; Pallàs Areny, Ramon (Institute of Electrical and Electronics Engineers, 2003-03)
    Article
    Open Access
    AC coupling is essential in biopotential measurements. Electrode offset potentials can be several orders of magnitude larger than the amplitudes of the biological signals of interest, thus limiting the admissible gain of ...
  • A comprehensive model for power line interference in biopotential measurements 

    Fernández Chimeno, Mireya; Pallàs Areny, Ramon (Institute of Electrical and Electronics Engineers, 2000-06-30)
    Article
    Open Access
    Power line interference is a major problem in high-resolution biopotential measurements. Because interference coupling is mostly capacitive, shielding electrode leads and a high common-mode rejection ratio (CMRR) are ...
  • A fast method to estimate body capacitance to ground 

    Aliau Bonet, Carles; Pallàs Areny, Ramon (2012)
    Conference report
    Open Access
  • A fast method to estimate body capacitance to ground at mid frequencies 

    Aliau Bonet, Carles; Pallàs Areny, Ramon (University of Oslo, 2015-12-18)
    Article
    Open Access
    Impedance measurements that involve the human body are affected by the capacitance between the body and earth ground. This paper describes a fast method to estimate that apacitance at 10 kHz, which is valid for impedance ...
  • A hands-on approach to differential circuit measurements 

    Pallàs Areny, Ramon; Casas Piedrafita, Óscar (Elsevier, 2007-01)
    Article
    Open Access
    Electronic engineering is showing a definite trend towards differential circuits. However, most measurement instruments are single-ended. Consequently, engineering graduates often lack the skills to perform correct ...
  • An algorithm for beat-to-beat heart rate detection from the BCG based on the continuous spline wavelet transform 

    Alvarado Serrano, Carlos; Luna Lozano, Pablo Samuel; Pallàs Areny, Ramon (2016-05-01)
    Article
    Restricted access - publisher's policy
    This work describes an algorithm intended to detect the beat-to-beat heart rate from the ballistocardiogram (BCG) obtained from seated subjects. The algorithm is based on the continuous wavelet transform with splines, which ...
  • An improved buffer for bioelectric signals 

    Pallàs Areny, Ramon; Colominas i Balagué, Josep; Rosell Ferrer, Francisco Javier (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1989-04-01)
    Article
    Open Access
    We propose an AC-coupled amplifier that offers a high in-put impedance, thus making it suitable for bioelectric signal amplifi- cation. We also present the necessary formulas for calculating its input impedance and transfer ...
  • A novel algorithm for fast BCG cycle extraction in ambulatory scenarios 

    Gomez Clapers, Joan; Casanella Alonso, Ramón; Pallàs Areny, Ramon (2016)
    Conference lecture
    Restricted access - publisher's policy
    A novel algorithm JDet for ballistocardiogram (BCG) cycle extraction is presented that is intended for the fast generation of ensemble averages in ambulatory scenarios where the ECG signal is not available. First, the ...
  • A novel fully differential biopotential amplifier with DC suppression 

    Spinelli, Enrique M.; Martínez, Nolberto; Mayosky, Miguel Ángel; Pallàs Areny, Ramon (Institute of Electrical and Electronics Engineers, 2004-08)
    Article
    Open Access
    Fully differential amplifiers yield large differential gains and also high common mode rejection ratio (CMRR), provided they do not include any unmatched grounded component. In biopotential measurements, however, the ...
  • A novel method to obtain proximal plethysmographic information from distal measurements using the impedance plethysmogram 

    Gómez Clapers, Joan; Casanella Alonso, Ramón; Pallàs Areny, Ramon (University of Oslo, 2015-12-23)
    Article
    Open Access
    We present a novel method to detect proximal volume changes based on the impedance plethysmogram (IPG) measured from limb to limb with two electrode pairs symmetrically placed at distal areas of the upper or the lower ...
  • 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 ...
  • A novel sensor-bridge-to-microcontroller interface 

    Custodio Ruiz, Ángel; Bragós Bardia, Ramon; Pallàs Areny, Ramon (Institute of Electrical and Electronics Engineers, 2001-05)
    Conference report
    Open Access
    Sensor bridges are usually interfaced to microcontrollers by supplying the bridge with a voltage or current and digitizing the resulting voltage or current after being amplified and low-pass filtered. This paper proposes ...
  • A practical approach to electrode-skin impedance unbalance measurement 

    Spinelli, Enrique M.; Mayosky, Miguel Ángel; Pallàs Areny, Ramon (Institute of Electrical and Electronics Engineers, 2006-07)
    Article
    Open Access
    Unbalance between electrode-skin impedances is a major problem in biopotential recordings, leading to increased power-line interference. This paper proposes a simple, direct method to measure that unbalance at power-line ...
  • Automatic Concealed Heart Rate Detection from the BCG in Seated Position 

    Luna Lozano, P. S.; Pallàs Areny, Ramon (2015-03-01)
    Article
    Open Access
    Continuous monitoring of health state is important in elder and chronically ill (but otherwise not critical) patients. Ideally, the patient should not be aware of being continuously monitored. This study describes an ...
  • Automatic detection of ECG ventricular activity waves using continuous spline wavelet transform 

    Alvarado Serrano, Carlos; Arregui, J.; Ramos Castro, Juan José; Pallàs Areny, Ramon (2005)
    Conference report
    Open Access
    In this study, we present detection algorithms of characteristic points of the QRS and T waves based on the continuous wavelet transform (CWT) with splines. This technique can handle any integer scale and the analysis is ...
  • La Bioingeniería en la Escuela 

    Pallàs Areny, Ramon (Escola Tècnica Superior d'Enginyers de Telecomunicació de Barcelona, 1993)
    Article
    Open Access
  • Charge-transfer-based signal interface for differential capacitive sensors 

    Gaitán Pitre, Jorge Elicer; Pallàs Areny, Ramon (2015)
    Conference lecture
    Open Access
    We propose a circuit to directly connect a differential capacitive sensor to a microcontroller unit (MCU), which is based on the charge-transfer method and does not need any calibration component. The performance has been ...
  • Charge-transfer-based signal interface for resistive sensors 

    Gaitán Pitre, Jorge Elicer; Pallàs Areny, Ramon (2015)
    Conference lecture
    Open Access
    Charge transfer has been demonstrated to be a cost-effective method to measure capacitive sensors with low-end microcontrollers. Here we apply charge transfer to measure the output of voltage dividers that include a high ...
  • Comments on "On resistor-induced thermal noise in linear circuits" 

    Vargas Drechsler, Manuel; Pallàs Areny, Ramon (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 2002-04-30)
    Working paper
    Open Access
    Correspondència referida a l'article de R. Giannetti, publicat ibid. vol.49 p.87-88
  • La Compatibilidad electromagnética, un problema en la sociedad actual 

    Pallàs Areny, Ramon; Silva, Ferran (Escola Tècnica Superior d'Enginyers de Telecomunicació de Barcelona, 1999)
    Article
    Open Access