Stochastic Resonance Based Latency Delay Estimation for Weak Evoked Potentials with Impulsive Noises

Abstract

This paper is to propose a novel robust time delay estimation approach (referred to as the SRCTDE) to detect the latency delay in the evoked potential (EP) with the presence of the Alpha-stable noise under the lower mixed-signal-to-noise ratio (MSNR) condition. The SRCTDE is based on the fractional lower order statistics (FLOS) and stochastic resonance (SR) technique. First MSNRs of the reference and detected EP signals are improved via the SR effect between noisy EP signals and bistable nonlinear dynamical systems. The SR effect is realized by tuning system parameters to their optimal values under the maximum symmetric covariation coefficient criterion. Then the covariation function between outputs of two SR systems is computed. The EP latency delay is estimated by obtaining the location of this covariation function peak. The performance of the SRCTDE algorithm is verified through computer simulations compared with the correlation and covariation algorithms for various values of MSNR and Alpha. The SRCTDE algorithm gives an improved approach to estimating the latency delay in the EP with Alpha-stable noises under the lower MSNR condition.