Biomedical subjects

Amine Naït-Ali

Publications and source records attributed to Amine Naït-Ali.

3 recordsLinked to original sources

PubMed2005

Parametrical modelling of a premature ventricular contraction ECG beat: comparison with the normal case.

The aim of this paper is to analyse a parametrical Gaussian kernel based model. The proposed model is tested on two types of electrocardiogram (ECG) beats, the normal case beat and the premature ventricular contraction (PVC) one. Basically, the model is constituted of N Gaussians where their corresponding parameters are estimated by optimising a specific criterion. The modelling technique has been validated using MIT/BIH databases. As a result of this study, we show that a normal beat can be modelled using 18 parameters and only 15 parameters are needed to reconstruct the PVC one.

Computer Simulation↗

PubMed2005

A new vision on the averaging technique for the estimation of non-stationary Brainstem Auditory-Evoked Potentials: application of a metaheuristic method.

The aim of this paper consists in highlighting the use of the averaging technique in some biomedical applications, such as evoked potentials (EP) extraction. We show that this technique, which is generally considered as classical, can be very efficient if the dynamic model of the signal to be estimated is a priori known. Therefore, using an appropriate model and under some specific conditions, one can show that the estimation can be performed efficiently even in case of a very low signal to noise ratio (SNR), which occurs when handling Brainstem Auditory-Evoked Potentials.

Acoustic Stimulation↗

PubMed2005

Fast simulated annealing algorithm for BAEP time delay estimation using a reduced order dynamic model.

The extraction of Brainstem Auditory Evoked Potentials (BAEPs), from the EEG background, is of high clinical interest. The present paper can be considered as a continuation of our previous work related to the BAEP estimation in endocochlear pathologies. In our previous published work, we proposed a technique for time delay estimation on the basis of the BAEPs in response to successive stimulations. Put in a different manner, our objective was the estimation of the dynamics of the cochlea that is responsible for the delayed responses. The estimation technique was based on optimization of a non-linear criterion by means of Simulated Annealing Time Delay Estimation (SATDE) algorithm. However, it is well known that such heuristic algorithms are time consuming and largely depend on the number of parameters to be estimated. The present paper demonstrates that modeling the non-stationarity of responses considerably decreases the convergence time to the global minimum. The newly proposed method in this paper, called Fast Simulated Annealing Time Delay Estimation (FSATDE) algorithm, has been validated on both simulated and real signals.

Algorithms↗