Method for filtering out artefacts of deep brain stimulation

Method for filtering a signal of neuronal activity during a high frequency deep brain stimulation (DBS) to remove a stimulus artefact in an observed signal, comprising:

• using an analysis unit:
• i) approximating the observed signal trajectories in phase space, by considering the observed signal as a sum of the stimulation artefacts induced by the signal of stimulation, and by assuming that the signal of stimulation is a solution of an ordinary differential equation including a self-oscillating system with stable limit cycle,
• ii) slicing the observed signal and its derivative into segments, each segment corresponding to a period of stimulation, and selecting N periods among the segments,
• iii) collecting the N selected periods of stimulation into a training set,
• iv) estimating the limit cycle of the self-oscillating system using the training set,
• v) synchronizing each stimulation artefact of the observed signal with the estimated limit cycle,
• vi) subtracting the estimated limit cycle from each artefact in phase space according to the synchronization,
• vii) collecting all segments in order to obtain a whole filtered signal, and
• viii) presenting the results in the time domain.