Stimulus artifact reduction in somatosensory evoked potential acquisition: a conceptual model

Stimulus artifact poses a distinct problem in somatosensory evoked potential recordings in that it is coherent with the evoked response, and thus cannot be reduced by ensemble averaging. This artifact is a voltage transient of the stimulus pulse and is not simply restricted to the duration of the pulse. It is also much larger in amplitude than the signal of interest, thus causing difficulty in analysis of the evoked response waveform. The authors have developed a conceptual model of the stimulus artifact interference in evoked potential signals. Experimental validation of this model is presented along with strategies to effectively reduce stimulus artifact in the clinical and research setting.