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.
-
Microphone array virtualization.
Optimized interpolation algorithm for microphone array beamforming.
-
P and T-wave delineation in ECG signals using a Bayesian approach
Matlab codes
. Technical report
.
Collaborations
Supports, grants and awards
2009-2012: |
Research doctoral fellowship from TéSA laboratory. |
2007-2009: |
Master scholarship from Rockwell Collins France. |