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Research activities

Research interests

Statistical signal processing. Biomedical signal processing. Audio processing.
Bayesian inference, hierarchical models.
MCMC methods: Gibbs sampling, Metropolis-Hastings, reversible jumps, hybrid algorithms....

Publications

List on the IRIT web server: here.

Ph.D. thesis

Detection of T-wave alternans in intra-cardiac signals

Advisor

Corinne Mailhes

Co-advisor

Jean-Yves Tourneret

Abstract

In the past few years, detection of T-Wave alternans (TWA) in electrocardiogram (ECG) signals has received growing interest, since it has been shown to be a potential sign of an up-to-coming cardiac problem. Detecting this phenomenon could be helpful to avoid sudden cardiac death. This phenomenon is characterized by a somehow periodic behaviour of the T-waves in ECGs. Several approaches for detecting this phenomenon have been proposed and further studies are always of interest, as shown by the challenge proposed in the last Computer in Cardiology (CINC) Conference. However, all studies have been done on surface ECGs, i.e. acquired using external sensors. There is a need to include such an early detection in intra-cardiac systems such as implantable cardioverter defibrillators (ICDs). Intra-cardiac ECGs, which are called EGMs (EndocardioGraMs) have properties different from ECGs in terms of Signal to Noise ratio, of noise behavior. Moreover, existing techniques are applied on windows of 128 or 256 beats which is not possible in an ICD where the detection has to be performed based on a few available successive beats (10 to 20). Furthermore, if TWA in surface ECGs appears as an alternan one over two successive beats, in intracardiac, it could happen with any other disorder: not only 1/2 but also 1/3, 1/4...
A pre-study has been done showing that parametric modeling can be one particularly promising approach. A detection strategy based on this parametric model combined with Bayesian inference will be investigated in this PhD work.
This work is partially supported by St. Jude Medical Inc. and in collaboration with Dr. Phillips Maury from the l'hôpital Rangueil de Toulouse.

Applications

For more details (simulation results, Matlab codes, papers...), click on the links when available.

Collaborations

Supports, grants and awards

2009-2012: Research doctoral fellowship from TéSA laboratory.
2007-2009: Master scholarship from Rockwell Collins France.