Papers by Leila Mirmohamadsadeghi
Computing in Cardiology 2014, Sep 7, 2014
ABSTRACT Estimating the respiratory rate (RR) from the electrocardiogram (ECG) is of interest as ... more ABSTRACT 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 tracks the common respiratory frequency which is present in its inputs as the RR estimate. On a subset of the Physionet MFH/MF dataset, it was shown that combining information from three leads yielded more accurate RR estimates than using two leads or each lead alone. It was also shown that the frequency tracking algorithm outperformed Fourier-based frequency estimation.
2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2015
The anaerobic threshold (AT) is a good index of personal endurance but needs a laboratory setting... more The anaerobic threshold (AT) is a good index of personal endurance but needs a laboratory setting to be determined. It is important to develop easy AT field measurements techniques in order to rapidly adapt training programs. In the present study, it is postulated that the variability of the respiratory parameters decreases with exercise intensity (especially at the AT level). The aim of this work was to assess, on healthy trained subjects, the putative relationships between the variability of some respiration parameters and the AT. The heart rate and respiratory variables (volume, rate) were measured during an incremental exercise performed on a treadmill by healthy moderately trained subjects. Results show a decrease in the variance of 1/tidal volume with the intensity of exercise. Consequently, the cumulated variance (sum of the variance measured at each level of the exercise) follows an exponential relationship with respect to the intensity to reach eventually a plateau. The amplitude of this plateau is closely related to the AT (r=-0.8). It is concluded that the AT is related to the variability of the respiration.
Biomedical Signal Processing and Control, 2014
ABSTRACT Monitoring the respiratory rate (RR) is important in many clinical and non-clinical situ... more ABSTRACT Monitoring the respiratory rate (RR) is important in many clinical and non-clinical situations but it is difficult in practice, for existing devices are obtrusive, bulky and expensive. The extraction of the RR from the routinely acquired electrocardiogram (ECG) has been proposed lately. Two approaches exist, one exploiting the modulation of the heart rate by the respiration, known as the respiratory sinus arrhythmia (RSA) and the other using the modulation by the respiration of the R-peak amplitudes (RPA). In this study, the weighted multi-signal oscillator based band pass filtering (W-OSC) algorithm is applied to track the common frequency in the RSA and RPA waveforms simultaneously, as an estimate of the instantaneous RR. On the public PhysioNet Fantasia data set, it is shown that the presented method is automatic, instantaneous and comparable in accuracy to the state-of-the-art.
2011 International Joint Conference on Biometrics (IJCB), 2011
ABSTRACT Palm vein feature extraction from near infrared images is a challenging problem in hand ... more ABSTRACT Palm vein feature extraction from near infrared images is a challenging problem in hand pattern recognition. In this paper, a promising new approach based on local texture patterns is proposed. First, operators and histograms of multi-scale Local Binary Patterns (LBPs) are investigated in order to identify new efficient descriptors for palm vein patterns. Novel higher-order local pattern descriptors based on Local Derivative Pattern (LDP) histograms are then investigated for palm vein description. Both feature extraction methods are compared and evaluated in the framework of verification and identification tasks. Extensive experiments on CASIA Multi-Spectral Palmprint Image Database V1.0 (CASIA database) identify the LBP and LDP descriptors which are better adapted to palm vein texture. Tests on the CASIA datasets also show that the best adapted LDP descriptors consistently outperform their LBP counterparts in both palm vein verification and identification.
2012 IEEE Fifth International Conference on Biometrics: Theory, Applications and Systems (BTAS), 2012
ABSTRACT Poor data quality is responsible for many or even most matching errors in fingerprint re... more ABSTRACT Poor data quality is responsible for many or even most matching errors in fingerprint recognition systems. It became obvious that particular effort is needed in adaptation of the state-of-the-art minutiae-based fingerprint matching techniques to real-world conditions using quality measures. In this paper, we address a challenging problem of how to associate local quality measures to local minutiae descriptors, in particular Minutia Cylinder-Code (MCC), in order to obtain better recognition rates. Firstly, we introduce a new local quality measure, called Cylinder Quality Measure (CQM), corresponding to each MCC descriptor by combining the qualities of individual minutiae involved. Then, we propose a method for incorporating such quality measures into fingerprint matching through a quality-based relaxation procedure. Our experiments on the FVC2002 (DB1 and DB3) and FVC2004 (DB3) databases demonstrate that integrating the cylinder quality measure through the proposed procedure improves the overall matching performance comparing to the state-of-the-art MCC based fingerprint matching algorithms.
ABSTRACT Estimating the respiratory rate (RR) from the electrocardiogram (ECG) is of interest as ... more ABSTRACT 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 tracks the common respiratory frequency which is present in its inputs as the RR estimate. On a subset of the Physionet MFH/MF dataset, it was shown that combining information from three leads yielded more accurate RR estimates than using two leads or each lead alone. It was also shown that the frequency tracking algorithm outperformed Fourier-based frequency estimation.
ABSTRACT It is important in biometric person recognition systems to protect personal data and pri... more ABSTRACT It is important in biometric person recognition systems to protect personal data and privacy of users. This paper introduces a new mechanism to revoke and protect fingerprint minutiae information, which can be used in today's security-aware society. The recently developed minutiae cylinder code (MCC), which provides rotation and translation invariant descriptors for accurate fingerprint recognition by describing minutiae neighborhoods with respect to each other, is used as baseline fingerprint descriptor. A hybrid scheme combining a transformation and a user key is designed to provide the MCC-based fingerprint representation with revocability and irreversibility properties for template privacy protection across multiple applications. Furthermore, using the publicly available FVC datasets, it is demonstrated that the designed scheme improves the baseline accuracy of fingerprint recognition using the MCC method.
mmspg.epfl.ch
Over the last few years, social network systems have greatly increased internet users' invol... more Over the last few years, social network systems have greatly increased internet users' involvement in content creation and annotation. These systems are characterized as easy-to-use and interactive. Users contribute with their opinion by annotating content (the so-called tagging), they add tags, comments and recommendations or rate the content.
2014 IEEE Biomedical Circuits and Systems Conference (BioCAS) Proceedings, 2014
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Papers by Leila Mirmohamadsadeghi