Abstract: The present invention relates to a method for filtering the signal of neuronal activity during a high frequency deep brain stimulation (DBS) to remove the stimulus artefact in the observed signal, comprising the step of approximating the observed signal trajectories in phase space the observed signal being considered as a sum of the stimulation artifacts induced by the signal of stimulation, wherein the signal of stimulation is assumed to be a solution of an ordinary differential equation including a self-oscillating system with stable limit cycle; slicing the observed signal and its derivative into segments, each segment corresponding to a period of stimulation; collecting N selected periods of stimulation to a training set; estimating the limit cycle of the self-oscillating system; synchronizing each artefact of the observed signal with the estimated limit cycle; subtracting the estimated limit cycle from each artefact in phase space according to the synchronization; collecting all segments in order to obta