5: Conclusion

L’analyse temporelle du signal du PEV et son exploitation, à travers la méthode de la latence pour la discrimination entre sujets sains et pathologiques, a montré ses limites. La réduction d’un signal aussi complexe que le PEV à un seul paramètre (la latence) nous parait discutable. Nous avons proposé et exposé dans ce chapitre le choix d’une analyse spectrale basée sur la méthode adaptative de Pisarenko associé à une structure en treillis normalisée.

Nous avons ainsi montré que cette méthode permet une estimation non biaisée des fréquences d’un signal en présence de bruit dans un environnement stationnaire ou non stationnaire et que l’algorithme converge suffisamment rapidement pour traquer l’évolution de ceux-ci dans le temps avec une bonne précision.

Dans le chapitre suivant nous exploiterons les résultats de cette méthode sur les potentiels évoqués visuels afin de proposer un algorithme de discrimination entre sujets sains et cas pathologiques qui pourrait apporter une aide aux neurophysiologistes dans leurs diagnostics.

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